Input Reference (exciting Helium)

This web page lists all elements and attributes that can be used in the input file of an exciting calculation:

• elements are defined according to the general XML conventions. Example: The element groundstate is used to set up a self-consistent calculation of the ground-state energy.
• attributes are defined according to the general XML conventions. An attribute is always connected to an element. In exciting an attribute generally specifies a parameter or a set of parameters which are connected to the corresponding element. Example: The attribute xctype of the element groundstate defines which exchange-correlation potential is used in the self-consistent calculation.

The input file of an exciting calculation is namedinput.xml. It must be a valid XML file, and it must contain the root element input.

Unless explicitly stated otherwise, exciting uses atomic units ( $\hbar = m_{e} = e = 1$ ):

• Energies are given in Hartree:

$1 Ha = 2 Ry = 27.21138386(68) eV = 4.35926 10^{-18}\ J$

• Lengths are given in Bohr:

$1 a_{\rm Bohr}\ = 0.52917720859(36) {\buildrel _{\circ} \over {\mathrm{A}}} \ = 0.52917720859(36) 10^{-10} \ m$

• Magnetic fields are given in units of

$1 a.u. = \displaystyle\frac{e}{a_{\rm Bohr}^2}\ = 1717.2445320376\ Tesla.$

Note: The electron charge is positive, so that the atomic numbers $Z$ are negative.

Element: input

The xml element input is the root element of the exciting input file. It must contain one element structure and the element groundstate .

Find a minimal input file instance described here.

contains:	title (1 times) structure (1 times) groundstate (optional) structureoptimization (optional) properties (optional) phonons (optional) xs (optional) keywords (optional)
XPath:	/input

This element allows for specification of the following attributes:

Attribute: scratchpath

This is the path to scratch space where the eigenvector files EVECFV.OUT, EVECSV.OUT and OCCSV.OUT will be written. If the local directory is accessed via a network then scrpath can be set to a directory on a local disk

Type:	anyURI
Use:	optional
XPath:	/input/@scratchpath

Attribute: xsltpath

Type:	anyURI
Default:	"http://xml.exciting-code.org"
Use:	optional
XPath:	/input/@xsltpath

Element: title

Title of the input file.

Type:	string
XPath:	/input/title

Element: structure

The structure element contains all structural information such as unit cell and atom positions.

contains:	crystal (1 times) species (zero or more)
XPath:	/input/structure

This element allows for specification of the following attributes:

Attribute: autormt

If "true" automatic determination of the muffin tin radii is allowed.

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/structure/@autormt

Attribute: epslat

Vectors with lengths less than this are considered zero.

Type:	fortrandouble
Default:	"1.0d-6"
Use:	optional
Unit:	Bohr
XPath:	/input/structure/@epslat

Attribute: molecule

Has to be set to "true" if one wants to calculate an isolated molecule. If it is "true" , then the atomic positions, ${\bf a}$ , are assumed to be in Cartesian coordinates. The lattice vectors are also set up automatically with the i-th lattice vector given by

(1)

\begin{align} {\bf A}^i=A_i\hat{\bf e}^i, \end{align}

where

(2)

\begin{align} A_i=\max_{\alpha,\beta}\left|{\bf a}^{\alpha}_i-{\bf a}^{\beta}_i\right| +d_{\rm vac} \end{align}

with $\alpha$ and $\beta$ labeling atoms, and $d_{\rm vac}$ determines the size of the vacuum around the molecule. The last variable is set by the attribute vacuum .

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/structure/@molecule

Attribute: primcell

Allows the primitive unit cell to be determined automatically from the conventional cell. This is done by searching for lattice vectors among all those which connect atomic sites, and using the three shortest ones which produce a unit cell with non-zero volume.

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/structure/@primcell

Attribute: speciespath

Gives the path to the directory containing the species files. It can be an HTTP URL too (needs wget ).

Type:	anyURI
Use:	required
XPath:	/input/structure/@speciespath

Attribute: tshift

Set to it to "true" if the crystal can be shifted such that the atom closest to the origin is exactly at the origin.

Type:	boolean
Default:	"true"
Use:	optional
XPath:	/input/structure/@tshift

Attribute: vacuum

Determines the size of the vacuum around the molecule.

Type:	fortrandouble
Default:	"10.0d0"
Use:	optional
Unit:	Bohr
XPath:	/input/structure/@vacuum

Element: crystal

Defines the unit cell of the crystal via the 3 basis vectors.

contains:	basevect (3 times)
XPath:	/input/structure/crystal

This element allows for specification of the following attributes:

Attribute: scale

Scales all the lattice vectors by the same factor. This is useful for varying the volume.

Type:	fortrandouble
Default:	"1.0d0"
Use:	optional
Unit:	1
XPath:	/input/structure/crystal/@scale

Attribute: stretch

Allows for an individual scaling of each lattice vector separately. "1 1 1" means no scaling.

Type:	vect3d
Default:	"1.0d0 1.0d0 1.0d0 "
Use:	optional
XPath:	/input/structure/crystal/@stretch

Element: basevect

Defines one basis vector in Cartesian coordinates.

Type:	vect3d
Unit:	Bohr
XPath:	/input/structure/crystal/basevect

Element: species

Defines the atomic species, i.e. the chemical element. The atomic coordinates and, optionally, quantities relevant for magnetic calculations are defined in the subelement(s) atom.

contains:	atom (1 times or more) LDAplusU (optional)
XPath:	/input/structure/species

This element allows for specification of the following attributes:

Attribute: atomicNumber

Optional attribute that may be used in visualization and by converters. It is not used in exciting

Type:	integer
Use:	optional
XPath:	/input/structure/species/@atomicNumber

Attribute: chemicalSymbol

Optional attribute that may be used in visualization and by converters. It is ignored by exciting

Type:	string
Default:	""
Use:	optional
XPath:	/input/structure/species/@chemicalSymbol

Attribute: href

Defines the address/URI of a species file provided in web. If this attribute is specified, all other attributes

Type:	anyURI
Default:	""
Use:	optional
XPath:	/input/structure/species/@href

Attribute: rmt

Defines the muffin-tin radius; this optional parameter allows to override species file or automatic determination. The muffin-tin radius defines the region around the atomic nucleus where the wave function is expanded in terms of atomic-like functions. In contrast, the interstitial region (=region not belonging to any muffin-tin) is described by planewaves.

Type:	fortrandouble
Default:	"-1.0d0"
Use:	optional
Unit:	Bohr
XPath:	/input/structure/species/@rmt

Attribute: speciesfile

Defines the file that contains the species definition. It is looked up in the species directory specified by the species path. By default, the name of the file is element.xml, e.g. Ag.xml.

Type:	anyURI
Use:	required
XPath:	/input/structure/species/@speciesfile

Element: atom

Defines the position and other attributes of one atom in the unit cell.

Type:	no content
XPath:	/input/structure/species/atom

This element allows for specification of the following attributes:

Attribute: bfcmt

Muffin-tin external magnetic field in Cartesian coordinates.

Type:	vect3d
Default:	"0.0d0 0.0d0 0.0d0"
Use:	optional
XPath:	/input/structure/species/atom/@bfcmt

Attribute: coord

Position in lattice coordinates.

Type:	vect3d
Use:	required
Unit:	lattice coordinates
XPath:	/input/structure/species/atom/@coord

Attribute: mommtfix

The desired muffin-tin moment for a Fixed Spin Moment (FSM) calculation.

Type:	vect3d
Default:	"0.0d0 0.0d0 0.0d0"
Use:	optional
XPath:	/input/structure/species/atom/@mommtfix

Element: LDAplusU

If present defines LDA plus U parameters for species

Type:	no content
XPath:	/input/structure/species/LDAplusU

This element allows for specification of the following attributes:

Attribute: J

Type:	fortrandouble
Default:	"0.0d0"
Use:	optional
XPath:	/input/structure/species/LDAplusU/@J

Attribute: U

Type:	fortrandouble
Default:	"0.0d0"
Use:	optional
XPath:	/input/structure/species/LDAplusU/@U

Attribute: l

Type:	integer
Default:	"-1"
Use:	optional
XPath:	/input/structure/species/LDAplusU/@l

Element: groundstate

The groundstate element is required for any calculation. Its attributes are the parameters and methods used to calculate the groundstate density.

contains:	spin (optional) solver (optional) output (optional) libxc (optional)
XPath:	/input/groundstate

This element allows for specification of the following attributes:

Attribute: autokpt

Decides if the k -point set is to be determined automatically

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/groundstate/@autokpt

Attribute: beta0

Initial value for mixing parameter. Used in linear mixing.

Type:	fortrandouble
Default:	"0.4d0"
Use:	optional
XPath:	/input/groundstate/@beta0

Attribute: betadec

Mixing parameter decrease. Used in linear mixing.

Type:	fortrandouble
Default:	"0.6d0"
Use:	optional
XPath:	/input/groundstate/@betadec

Attribute: betainc

Mixing parameter increase. Used in linear mixing.

Type:	fortrandouble
Default:	"1.1d0"
Use:	optional
XPath:	/input/groundstate/@betainc

Attribute: cfdamp

Damping coefficient for characteristic function.

Type:	fortrandouble
Default:	"0.0d0"
Use:	optional
XPath:	/input/groundstate/@cfdamp

Attribute: chgexs

This controls the amount of charge in the unit cell beyond that required to maintain neu-trality. It can be set positive or negative depending on whether electron or hole doping is required.

Type:	fortrandouble
Default:	"0.0d0"
Use:	optional
XPath:	/input/groundstate/@chgexs

Attribute: deband

Initial band energy step size The initial step length used when searching for the band energy, which is used as the APW linearization energy. This is done by first searching upwards in energy until the radial wavefunction at the muffin-tin radius is zero. This is the energy at the top of the band, denoted $E_{\rm t}$ . A downward search is now performed from $E_{\rm t}$ until the slope of the radial wavefunction at the muffin-tin radius is zero. This energy, $E_{\rm b}$ , is at the bottom of the band. The band energy is taken as $(E_{\rm t}+E_{\rm b})/2$ . If either $E_{\rm t}$ or $E_{\rm b}$ cannot be found then the band energy is set to the default value.

Type:	fortrandouble
Default:	"0.0025d0"
Use:	optional
Unit:	Hartree
XPath:	/input/groundstate/@deband

Attribute: dlinengyfermi

Energy difference between linearisation and Fermi energy.

Type:	fortrandouble
Default:	"-0.1d0"
Use:	optional
Unit:	Hartree
XPath:	/input/groundstate/@dlinengyfermi

Attribute: do

Decides if the groundstate run is skipped, calculated from scratch, or continued from the file STATE.OUT.

Type:	choose from: fromscratch fromfile skip fromscratch skip fromscratch fromkernel fromscratch skip
Default:	"fromscratch"
Use:	optional
XPath:	/input/xs/screening/@do

Attribute: epsband

Energy tolerance for search of linearization energies.

Type:	fortrandouble
Default:	"1.0d-6"
Use:	optional
Unit:	Hartree
XPath:	/input/groundstate/@epsband

Attribute: epschg

Maximum allowed error in the calculated total charge beyond which a warning message will be issued.

Type:	fortrandouble
Default:	"1.0d-3"
Use:	optional
XPath:	/input/groundstate/@epschg

Attribute: epsengy

Energy convergence tolerance.

Type:	fortrandouble
Default:	"1.0d-4"
Use:	optional
Unit:	Hartree
XPath:	/input/groundstate/@epsengy

Attribute: epsforce

Convergence tolerance for the forces during the SCF run.

Type:	fortrandouble
Default:	"5.0d-5"
Use:	optional
XPath:	/input/groundstate/@epsforce

Attribute: epsocc

smallest occupancy for which a state will contribute to the density.

Type:	fortrandouble
Default:	"1.0d-8"
Use:	optional
XPath:	/input/groundstate/@epsocc

Attribute: epspot

If the RMS change in the effective potential and magnetic field is smaller than epspot , then the self-consistent loop is considered converged and exited. For structural optimization runs this results in the forces being calculated, the atomic positions updated and the loop restarted. See also maxscl.

Type:	fortrandouble
Default:	"1.0d-6"
Use:	optional
XPath:	/input/groundstate/@epspot

Attribute: fermilinengy

If "true" the linearization energies marked as non-varying are set to the Fermi level plus dlinengyfermi .

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/groundstate/@fermilinengy

Attribute: findlinentype

Select method to determine the linearization energies.

Type:	choose from: simple advanced
Default:	"advanced"
Use:	optional
XPath:	/input/groundstate/@findlinentype

Attribute: fracinr

Fraction of the muffin-tin radius up to which lmaxinr is used as the angular momentum cut-off.

Type:	fortrandouble
Default:	"0.25d0"
Use:	optional
XPath:	/input/groundstate/@fracinr

Attribute: frozencore

When set to "true" the frozen core approximation is applied, i.e., the core states are fixed to the atomic states.

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/groundstate/@frozencore

Attribute: gmaxvr

Maximum length of |G| for expanding the interstitial density and potential.

Type:	fortrandouble
Default:	"12.0d0"
Use:	optional
XPath:	/input/groundstate/@gmaxvr

Attribute: isgkmax

Species for which the muffin-tin radius will be used for calculating gkmax.

Type:	integer
Default:	"-1"
Use:	optional
XPath:	/input/groundstate/@isgkmax

Attribute: ldapu

Type of LDA+U method to be used.

Type:	choose from: none FullyLocalisedLimit AroundMeanField FFL-AMF-interpolation
Default:	"none"
Use:	optional
XPath:	/input/groundstate/@ldapu

Attribute: lmaxapw

Angular momentum cut-off for the APW functions.

Type:	integer
Default:	"10"
Use:	optional
XPath:	/input/groundstate/@lmaxapw

Attribute: lmaxinr

Close to the nucleus, the density and potential is almost spherical and therefore the spherical harmonic expansion can be truncated a low angular momentum. See also fracinr.

Type:	integer
Default:	"2"
Use:	optional
XPath:	/input/groundstate/@lmaxinr

Attribute: lmaxmat

Angular momentum cut-off for the outer-most loop in the hamiltonian and overlap matrix setup.

Type:	integer
Default:	"5"
Use:	optional
XPath:	/input/groundstate/@lmaxmat

Attribute: lmaxvr

Angular momentum cut-off for the muffin-tin density and potential.

Type:	integer
Default:	"6"
Use:	optional
XPath:	/input/groundstate/@lmaxvr

Attribute: lradstep

Some muffin-tin functions (such as the density) are calculated on a coarse radial mesh and then interpolated onto a fine mesh. This is done for the sake of efficiency. lradstp defines the step size in going from the fine to the coarse radial mesh. If it is too large, loss of precision may occur.

Type:	integer
Default:	"4"
Use:	optional
XPath:	/input/groundstate/@lradstep

Attribute: maxscl

Upper limit for te selfconsistency loop.

Type:	integer
Default:	"200"
Use:	optional
XPath:	/input/groundstate/@maxscl

Attribute: mixer

select the mixing (relaxation) scheme for SCF

Type:	choose from: lin msec pulay
Default:	"msec"
Use:	optional
XPath:	/input/groundstate/@mixer

Attribute: nempty

Defines the number of eigenstates beyond that required for charge neutrality. When running metals it is not known a priori how many states will be below the Fermi energy for each k -point. Setting nempty greater than zero allows the additional states to act as a buffer in such cases. Furthermore, magnetic calculations use the first-variational eigenstates as a basis for setting up the second-variational Hamiltonian, and thus nempty will determine the size of this basis set. Convergence with respect to this quantity should be checked.

Type:	integer
Default:	"5"
Use:	optional
XPath:	/input/groundstate/@nempty

Attribute: ngridk

Number of k grid points along the basis vector directions.

Type:	integertriple
Use:	required
XPath:	/input/groundstate/@ngridk

Attribute: nktot

Used for the automatic determination of the k-point mesh from the total number of k-points. If nktot is set, then the mesh will be determined in such a way that the number of-points is proportional to the length of the reciprocal lattice vector in each direction and that the total number of k-points is less than or equal to nktot .

Type:	integer
Default:	""
Use:	optional
XPath:	/input/groundstate/@nktot

Attribute: nosource

When set to "true" , source fields are projected out of the exchange-correlation magnetic field. experimental feature.

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/groundstate/@nosource

Attribute: nosym

When set to "true" no symmetries, apart from the identity, are used anywhere in the code.

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/groundstate/@nosym

Attribute: nprad

Smallest occupancy for which a state will contribute to the density.

Type:	integer
Default:	"4"
Use:	optional
XPath:	/input/groundstate/@nprad

Attribute: npsden

oOrder of polynomial for pseudocharge density.

Type:	integer
Default:	"9"
Use:	optional
XPath:	/input/groundstate/@npsden

Attribute: nwrite

Normally, the density and potentials are written to the file STATE.OUT only after com- pletion of the self-consistent loop. By setting nwrite to a positive integer the file will be written during the loop every nwrite iterations.

Type:	integer
Default:	""
Use:	optional
XPath:	/input/groundstate/@nwrite

Attribute: ptnucl

The attrubute ptnucl is "true" if the nuclei are to be treated as point charges, if "false" the nuclei have a finite spherical distribution.

Type:	boolean
Default:	"true"
Use:	optional
XPath:	/input/groundstate/@ptnucl

Attribute: radkpt

Used for the automatic determination of the k -point mesh. If autokpt is set to "true" then the mesh sizes will be determined by $n_i=\lambda/|{ \bf A}_i|+1$ .

Type:	fortrandouble
Default:	"40.0d0"
Use:	optional
XPath:	/input/groundstate/@radkpt

Attribute: reducek

If the attribute reducek is "true" the $\bf{k}$ -point set is reduced with the crystal symmetries.

Type:	boolean
Default:	"true"
Use:	optional
XPath:	/input/groundstate/@reducek

Attribute: rgkmax

The parameter rgkmax implicitly determines the number of basis functions and is one of the crucial parameters for the accuracy of the calculation. It represents the product of two quantities: $R_{MT,\, Min}$ , the smallest of all muffin-tin radii, and $|{ \bf G}+{ \bf k}|_{max}$ , the maximum length for the ${ \bf G}+{ \bf k}$ \ vectors. Because each ${ \bf G}+{ \bf k}$ \ vector represents one basis function, rgkmax gives the number of basis functions used for solving the Kohn-Sham equations. Typical values of rgkmax are between 6 and 9. However, for systems with very short bond-lengths, significantly smaller values may be sufficient. This may especially be the case for materials containing carbon, where rgkmax may be 4.5-5, or hydrogen, where even values between 3 and 4 may be sufficient. In any case, a convergence check is indispensible for a proper choice of this parameter for your system!

Type:	fortrandouble
Default:	"7.0d0"
Use:	optional
XPath:	/input/groundstate/@rgkmax

Attribute: rmtapm

Parameters governing the automatic generation of the muffin-tin radii. When autormtis set to "true" , the muffin-tin radii are found automatically from the formula

(3)

\begin{align} R_i\propto 1+\zeta|Z_i|^{1/3}, \end{align}

where $Z_i$ is the atomic number of the $i$ th species, $\zeta$ is stored in rmtapm(1) and the value which governs the distance between the muffin-tins is stored in rmtapm(2). When rmtapm(2) =1, the closest muffin-tins will touch.

Type:	vect2d
Default:	"0.25d0 0.95d0"
Use:	optional
XPath:	/input/groundstate/@rmtapm

Attribute: stype

A smooth approximation to the Dirac delta function is needed to compute the occupancies of the Kohn-Sham states. The attribute swidth determines the width of the approximate delta function.

Type:	choose from: Gaussian Methfessel-Paxton 1 Methfessel-Paxton 2 Fermi Dirac Square-wave impulse
Default:	"Gaussian"
Use:	optional
XPath:	/input/groundstate/@stype

Attribute: swidth

Width of the smooth approximation to the Dirac delta function (must be greater than zero).

Type:	fortrandouble
Default:	"0.001d0"
Use:	optional
Unit:	Hartree
XPath:	/input/groundstate/@swidth

Attribute: symmorph

When set to "true" only symmorphic space-group operations are to be considered, i.e. only symmetries without non-primitive translations are used anywhere in the code.

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/groundstate/@symmorph

Attribute: tevecsv

The attribute tevecsv is "true" if second-variational eigenvectors are calculated.

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/groundstate/@tevecsv

Attribute: tfibs

Because calculation of the incomplete basis set (IBS) correction to the force is fairly time- consuming, it can be switched off by setting tfibs to "false" This correction can then be included only when necessary, i.e. when the atoms are close to equilibrium in a structural relaxation run.

Type:	boolean
Default:	"true"
Use:	optional
XPath:	/input/groundstate/@tfibs

Attribute: tforce

Decides if the force should be calculated at the end of the self-consistent cycle.

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/groundstate/@tforce

Attribute: vkloff

The k-point offset vector in lattice coordinates.

Type:	vect3d
Default:	"0.0d0 0.0d0 0.0d0"
Use:	optional
XPath:	/input/groundstate/@vkloff

Attribute: xctype

Type of exchange-correlation functional to be used

• No exchange-correlation funtional ( $E_{\rm xc}\equiv 0$ )
• LDA, Perdew-Zunger/Ceperley-Alder, Phys. Rev. B 23 , 5048 (1981)
• LSDA, Perdew-Wang/Ceperley-Alder, Phys. Rev. B 45 , 13244 (1992)
• LDA, X-alpha approximation, J. C. Slater, Phys. Rev. 81 , 385 (1951)
• LSDA, von Barth-Hedin, J. Phys. C 5 , 1629 (1972)
• GGA, Perdew-Burke-Ernzerhof, Phys. Rev. Lett. 77 , 3865 (1996)
• GGA, Revised PBE, Zhang-Yang, Phys. Rev. Lett. 80 , 890 (1998)
• GGA, PBEsol, arXiv:0707.2088v1 (2007)
• GGA, Wu-Cohen exchange (WC06) with PBE correlation, Phys. Rev. B 73 , 235116 (2006)
• GGA, Armiento-Mattsson (AM05) spin-unpolarised functional, Phys. Rev. B 72 , 085108 (2005)

Type:	choose from: LDAPerdew-Zunger LSDAPerdew-Wang LDA-X-alpha LSDA-Barth-Hedin GGAPerdew-Burke-Ernzerhof GGArevPBE GGAPBEsol GGA-Wu-Cohen GGAArmiento-Mattsson EXX none
Default:	"LSDAPerdew-Wang"
Use:	optional
XPath:	/input/groundstate/@xctype

Element: spin

If the spin element is present calculation is done with spin polarization.

Type:	no content
XPath:	/input/groundstate/spin

This element allows for specification of the following attributes:

Attribute: bfieldc

Alows to apply a constant B field This is a constant magnetic field applied throughout the entire unit cell and enters the second-variational Hamiltonian as

(4)

\begin{align} \frac{g_e\alpha}{4}\,\vec{\sigma}\cdot{\bf B}_{\rm ext}, \end{align}

where $g_e$ is the electron $g$ -factor (2.0023193043718). This field is normally used to break spin symmetry for spin-polarised calculations and considered to be infinitesimal with no direct contribution to the total energy. In cases where the magnetic field is finite (for example when computing magnetic response) the external ${ \bf B}$ -field energy reported in INFO.OUT should be added to the total by hand. This field is applied throughout the entire unit cell. To apply magnetic fields in particular muffin-tins use the bfcmt vect ors in the atoms block. Collinear calculations are more efficient if the field is applied in the $z$ -direction.

Type:	vect3d
Default:	"0.0d0 0.0d0 0.0d0 "
Use:	optional
XPath:	/input/groundstate/spin/@bfieldc

Attribute: fixspin

Type:	choose from: none total FSM localmt FSM both
Default:	"none"
Use:	optional
XPath:	/input/groundstate/spin/@fixspin

Attribute: momfix

The desired total moment for a FSM calculation.

Type:	vect3d
Default:	"0.0d0 0.0d0 0.0d0"
Use:	optional
XPath:	/input/groundstate/spin/@momfix

Attribute: reducebf

After each iteration the external magnetic fields are multiplied with reducebf. This al- lows for a large external magnetic field at the start of the self-consistent loop to break spin symmetry, while at the end of the loop the field will be effectively zero, i.e. infinitesimal. See bfieldcand atom element.

Type:	fortrandouble
Default:	"1.0d0"
Use:	optional
XPath:	/input/groundstate/spin/@reducebf

Attribute: spinorb

If spinorb is "true" , then a $\boldsymbol \sigma\cdot{ \bf L}$ term is added to the second-variational Hamiltonian.

Type:	boolean
Use:	optional
XPath:	/input/groundstate/spin/@spinorb

Attribute: spinsprl

Set to "true" if a spin-spiral calculation is required. Experimental feature for the calculation of spin-spiral states. See vqlssfor details.

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/groundstate/spin/@spinsprl

Attribute: taufsm

Type:	fortrandouble
Default:	"0.01d0"
Use:	optional
XPath:	/input/groundstate/spin/@taufsm

Attribute: vqlss

Is the ${ \bf q}$ -vector of the spin-spiral state in lattice coordinates. Spin-spirals arise from spinor states assumed to be of the form

(5)

\begin{align} \Psi^{ \bf q}_{ \bf k}({ \bf r})= \left( \begin{array}{c} U^{{\bf q}\uparrow}_{ \bf k}({\bf r})e^{i({ \bf k+q/2})\cdot{ \bf r}} \\ U^{{ \bf q}\downarrow}_{\bf k}({ \bf r})e^{i({\bf k-q/2})\cdot{ \bf r}} \\ \end{array} \right). \end{align}

These are determined using a second-variational approach, and give rise to a magnetization density of the form

(6)

\begin{align} {\bf m}^{ \bf q}({ \bf r})=(m_x({\bf r})\cos({ \bf q \cdot r}), m_y({\bf r})\sin({ \bf q \cdot r}),m_z({\bf r})), \end{align}

where $m_x$ , $m_y$ and $m_z$ are lattice periodic. See also spinprl.

Type:	vect3d
Default:	"0.0d0 0.0d0 0.0d0"
Use:	optional
XPath:	/input/groundstate/spin/@vqlss

Element: solver

Optional configuration options for eigenvector solver.

Type:	no content
XPath:	/input/groundstate/solver

This element allows for specification of the following attributes:

Attribute: epsarpack

Tolerance parameter for the ARPACK shift invert solver

Type:	fortrandouble
Default:	"1.0d-8"
Use:	optional
XPath:	/input/groundstate/solver/@epsarpack

Attribute: evaltol

Error tolerance for the first-variational eigenvalues using the LAPACK Solver

Type:	fortrandouble
Default:	"1.0d-8"
Use:	optional
Unit:	Hartree
XPath:	/input/groundstate/solver/@evaltol

Attribute: packedmatrixstorage

In the default calculation the matrix is sored in packed form. When using multithreaded BLAS setting this parmeter to "false" increases efficiency.

Type:	boolean
Default:	"true"
Use:	optional
XPath:	/input/groundstate/solver/@packedmatrixstorage

Attribute: type

Selects the eigenvalue solver for the first variational equation

Type:	choose from: Lapack Arpack DIIS
Default:	"Lapack"
Use:	optional
XPath:	/input/groundstate/solver/@type

Element: output

Specifications on the file formats for output files.

Type:	no content
XPath:	/input/groundstate/output

This element allows for specification of the following attributes:

Attribute: state

Selects the file format of the STATE file.

Type:	choose from: binary XML
Default:	"binary"
Use:	optional
XPath:	/input/groundstate/output/@state

Element: libxc

Type:	no content
XPath:	/input/groundstate/libxc

This element allows for specification of the following attributes:

Attribute: correlation

Type:	choose from: XC_LDA_C_WIGNER XC_LDA_C_RPA XC_LDA_C_HL XC_LDA_C_GL XC_LDA_C_XALPHA XC_LDA_C_VWN XC_LDA_C_VWN_RPA XC_LDA_C_PZ XC_LDA_C_PZ_MOD XC_LDA_C_OB_PZ XC_LDA_C_PW XC_LDA_C_PW_MOD XC_LDA_C_OB_PW XC_LDA_C_2D_AMGB XC_LDA_C_2D_PRM XC_LDA_C_vBH XC_LDA_C_1D_CSC XC_GGA_C_PBE XC_GGA_C_LYP XC_GGA_C_P86 XC_GGA_C_PBE_SOL XC_GGA_C_PW91 XC_GGA_C_AM05 XC_GGA_C_XPBE XC_GGA_C_LM XC_GGA_C_PBE_JRGX
Default:	"XC_GGA_C_PBE"
Use:	optional
XPath:	/input/groundstate/libxc/@correlation

Attribute: exchange

Type:	choose from: XC_LDA_X XC_LDA_X_2D XC_GGA_X_PBE XC_GGA_X_PBE_R XC_GGA_X_B86 XC_GGA_X_B86_R XC_GGA_X_B86_MGC XC_GGA_X_B88 XC_GGA_X_G96 XC_GGA_X_PW86 XC_GGA_X_PW91 XC_GGA_X_OPTX XC_GGA_X_DK87_R1 XC_GGA_X_DK87_R2 XC_GGA_X_LG93 XC_GGA_X_FT97_A XC_GGA_X_FT97_B XC_GGA_X_PBE_SOL XC_GGA_X_RPBE XC_GGA_X_WC XC_GGA_X_mPW91 XC_GGA_X_AM05 XC_GGA_X_PBEA XC_GGA_X_MPBE XC_GGA_X_XPBE XC_GGA_X_2D_B86_MGC XC_GGA_X_BAYESIAN XC_GGA_X_PBE_JSJR
Default:	"XC_GGA_X_PBE"
Use:	optional
XPath:	/input/groundstate/libxc/@exchange

Attribute: xc

Combined functionals. If set it overrides the exchange and the correlation attributes.

Type:	choose from: none XC_GGA_XC_LB XC_GGA_XC_HCTH_93 XC_GGA_XC_HCTH_120 XC_GGA_XC_HCTH_147 XC_GGA_XC_HCTH_407 XC_GGA_XC_EDF1 XC_GGA_XC_XLYP XC_GGA_XC_B97 XC_GGA_XC_B97_1 XC_GGA_XC_B97_2 XC_GGA_XC_B97_D XC_GGA_XC_B97_K XC_GGA_XC_B97_3 XC_GGA_XC_PBE1W XC_GGA_XC_MPWLYP1W XC_GGA_XC_PBELYP1W XC_GGA_XC_SB98_1a XC_GGA_XC_SB98_1b XC_GGA_XC_SB98_1c XC_GGA_XC_SB98_2a XC_GGA_XC_SB98_2b XC_GGA_XC_SB98_2c XC_HYB_GGA_XC_B3PW91 XC_HYB_GGA_XC_B3LYP XC_HYB_GGA_XC_B3P86 XC_HYB_GGA_XC_O3LYP XC_HYB_GGA_XC_mPW1K XC_HYB_GGA_XC_PBEH XC_HYB_GGA_XC_B97 XC_HYB_GGA_XC_B97_1 XC_HYB_GGA_XC_B97_2 XC_HYB_GGA_XC_X3LYP XC_HYB_GGA_XC_B1WC XC_HYB_GGA_XC_B97_K XC_HYB_GGA_XC_B97_3 XC_HYB_GGA_XC_mPW3PW XC_HYB_GGA_XC_B1LYP XC_HYB_GGA_XC_B1PW91 XC_HYB_GGA_XC_mPW1PW XC_HYB_GGA_XC_mPW3LYP XC_HYB_GGA_XC_SB98_1a XC_HYB_GGA_XC_SB98_1b XC_HYB_GGA_XC_SB98_1c XC_HYB_GGA_XC_SB98_2a XC_HYB_GGA_XC_SB98_2b XC_HYB_GGA_XC_SB98_2c
Default:	"none"
Use:	optional
XPath:	/input/groundstate/libxc/@xc

Element: structureoptimization

The structure optimization element triggers if present a geometry relaxation.

Type:	no content
XPath:	/input/structureoptimization

This element allows for specification of the following attributes:

Attribute: epsforce

Convergence tolerance for the forces during a structural optimization run.

Type:	fortrandouble
Default:	"5.0d-5"
Use:	optional
XPath:	/input/structureoptimization/@epsforce

Attribute: resume

Resumption of structural optimization run using density in STATE.OUT but with positions from input.xml .

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/structureoptimization/@resume

Attribute: tau0atm

The step size to be used for structural optimization

The position of atom $\alpha$ is updated on step $m$ of a structural optimization run using

(7)

\begin{align} {\bf r}_{\alpha}^{m+1}={\bf r}_{\alpha}^m+\tau_{\alpha}^m \left({ \bf F}_{\alpha}^m+{ \bf F}_{\alpha}^{m-1}\right), \end{align}

where $\tau_{\alpha}$ is set to tau0atm for $m=0$ , and incremented by the same amount if the atom is moving in the same direction between steps. If the direction changes then $\tau_{\alpha}$ is reset to tau0atm .

Type:	fortrandouble
Default:	"0.2d0"
Use:	optional
XPath:	/input/structureoptimization/@tau0atm

Element: properties

Properties listed in this element can be calculated from the groundstate. It works also from a saved state from a previous run.

contains:

bandstructure (optional) STM (optional) wfplot (optional) dos (optional) LSJ (optional) masstensor (optional) chargedensityplot (optional) exccplot (optional) elfplot (optional) mvecfield (optional) xcmvecfield (optional) electricfield (optional) gradmvecfield (optional) fermisurfaceplot (optional) EFG (optional) mossbauer (optional) momentummatrix (optional) dielectric (optional) moke (optional) expiqr (optional) elnes (optional) eliashberg (optional)

XPath:

/input/properties

Element: bandstructure

If present a banstructure is calculated.

contains:	plot1d
XPath:	/input/properties/bandstructure

This element allows for specification of the following attributes:

Attribute: character

Band structure plot which includes angular momentum characters for every atom.

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/properties/bandstructure/@character

Attribute: scissor

Value to shift bandgap.

Type:	fortrandouble
Default:	"0.0d0"
Use:	optional
Unit:	Hartree
XPath:	/input/properties/bandstructure/@scissor

Element: STM

contains:	plot2d (optional)
XPath:	/input/properties/STM

Element: wfplot

Wavefunction plot.

contains:	kstlist (optional) plot1d (optional) plot2d (optional) plot3d (optional)
XPath:	/input/properties/wfplot

Element: dos

If present a DOS calculation is started.

DOS and optics plots require integrals of the kind

(8)

\begin{align} g(\omega_i)=\frac{\Omega}{(2\pi)^3}\int_{\rm BZ} f({ \bf k}) \delta(\omega_i-e({\bf k}))d{ \bf k}. \end{align}

These are calculated by first interpolating the functions $e({ \bf k})$ and $f({ \bf k})$ with the trilinear method on a much finer mesh whose size is determined by ngrdos . Then the $\omega$ -dependent histogram of the integrand is accumulated over the fine mesh. If the output function is noisy then either ngrdos should be increased or nwdos decreased. Alternatively, the output function can be artificially smoothed up to a level given by nsmdos . This is the number of successive 3-point averages to be applied to the function $g$ .

Type:	no content
XPath:	/input/properties/dos

This element allows for specification of the following attributes:

Attribute: lmirep

When lmirep is set to "true" , the spherical harmonic basis is transformed into one in which the site symmetries are block diagonal. Band characters determined from the density matrix expressed in this basis correspond to irreducible representations, and allow the partial DOS to be resolved into physically relevant contributions, for example eg and t2g.

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/properties/dos/@lmirep

Attribute: ngrdos

Type:	integer
Default:	"100"
Use:	optional
XPath:	/input/properties/dos/@ngrdos

Attribute: nsmdos

Type:	integer
Default:	""
Use:	optional
XPath:	/input/properties/dos/@nsmdos

Attribute: nwdos

Type:	integer
Default:	"500"
Use:	optional
XPath:	/input/properties/dos/@nwdos

Attribute: scissor

Type:	fortrandouble
Default:	"0.0d0"
Use:	optional
Unit:	Hartree
XPath:	/input/properties/dos/@scissor

Attribute: sqados

Spin-quantization axis in Cartesian coordinates used when plotting the spin-resolved DOS (z-axis by default).

Type:	vect3d
Default:	"0.0d0 0.0d0 1.0d0"
Use:	optional
XPath:	/input/properties/dos/@sqados

Attribute: winddos

Frequency/energy window for the DOS or optics plot.

Type:	vect2d
Default:	"-0.5d0 0.5d0"
Use:	optional
Unit:	Hartree
XPath:	/input/properties/dos/@winddos

Element: LSJ

Output L, S and J expectation values.

contains:	kstlist
XPath:	/input/properties/LSJ

Element: masstensor

Compute the effective mass tensor at the k -point given by vklem.

Type:	no content
XPath:	/input/properties/masstensor

This element allows for specification of the following attributes:

Attribute: deltaem

The size of the k-vector displacement used when calculating numerical derivatives for the effective mass tensor.

Type:	fortrandouble
Default:	"0.025d0"
Use:	optional
XPath:	/input/properties/masstensor/@deltaem

Attribute: ndspem

The number of k-vector displacements in each direction around vklem when computing the numerical derivatives for the effective mass tensor.

Type:	integer
Default:	"1"
Use:	optional
XPath:	/input/properties/masstensor/@ndspem

Attribute: vklem

The k-point in lattice coordinates at which to compute the effective mass tensors.

Type:	vect3d
Default:	"0.0d0 0.0d0 0.0d0"
Use:	optional
XPath:	/input/properties/masstensor/@vklem

Element: chargedensityplot

Plot the charge density

contains:	plot1d (optional) plot2d (optional) plot3d (optional)
XPath:	/input/properties/chargedensityplot

Element: exccplot

Exchange-correlation and Coulomb potential plots.

contains:	plot1d (optional) plot2d (optional) plot3d (optional)
XPath:	/input/properties/exccplot

Element: elfplot

Electron localization function (ELF).

contains:	plot1d (optional) plot2d (optional) plot3d (optional)
XPath:	/input/properties/elfplot

Element: mvecfield

Plot of magnetization vector field.

contains:	plot2d (optional) plot3d (optional)
XPath:	/input/properties/mvecfield

Element: xcmvecfield

Plot of exchange-correlation magnetic vector field.

contains:	plot2d (optional) plot3d (optional)
XPath:	/input/properties/xcmvecfield

Element: electricfield

Writes the electric field to file.

contains:	plot2d (optional) plot3d (optional)
XPath:	/input/properties/electricfield

Element: gradmvecfield

Plot of he gradient of the magnetic vector field.

contains:	plot1d (optional) plot2d (optional) plot3d (optional)
XPath:	/input/properties/gradmvecfield

Element: fermisurfaceplot

Writes Fermi surface data to file.

Type:	no content
XPath:	/input/properties/fermisurfaceplot

This element allows for specification of the following attributes:

Attribute: nstfsp

Number of states to be included in the Fermi surface plot file.

Type:	integer
Default:	"6"
Use:	optional
XPath:	/input/properties/fermisurfaceplot/@nstfsp

Attribute: separate

Type:	boolean
Use:	optional
XPath:	/input/properties/fermisurfaceplot/@separate

Element: EFG

Calculation of electric field gradient (EFG), contact charge.

Type:	no content
XPath:	/input/properties/EFG

Element: mossbauer

Type:	no content
XPath:	/input/properties/mossbauer

Element: momentummatrix

Matrix elements of the momentum operator (legacy version, required by dielectric-element).

Type:	no content
XPath:	/input/properties/momentummatrix

This element allows for specification of the following attributes:

Attribute: fastpmat

apply generalised DFT correction of L. Fritsche and Y. M. Gu, Phys. Rev. B 48, 4250 (1993)

Type:	boolean
Default:	"true"
Use:	optional
XPath:	/input/properties/momentummatrix/@fastpmat

Element: dielectric

Linear optical response (without local field effects, legacy version).

contains:	optcomp
XPath:	/input/properties/dielectric

This element allows for specification of the following attributes:

Attribute: intraband

The intraband attribute is "true" if the intraband term is to be added to the optical matrix (q=0)

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/properties/dielectric/@intraband

Attribute: scissor

Type:	fortrandouble
Default:	"0.0d0"
Use:	optional
Unit:	Hartree
XPath:	/input/properties/dielectric/@scissor

Attribute: usegdft

apply generalised DFT correction of L. Fritsche and Y. M. Gu, Phys. Rev. B 48, 4250 (1993)

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/properties/dielectric/@usegdft

Element: optcomp

The components of the first- or second-order optical tensor to be calculated.

Type:	integertriple
Default:	"1 1 1"
XPath:	/input/properties/dielectric/optcomp

Element: moke

Type:	no content
XPath:	/input/properties/moke

Element: expiqr

Type:	no content
XPath:	/input/properties/expiqr

Element: elnes

Type:	no content
XPath:	/input/properties/elnes

This element allows for specification of the following attributes:

Attribute: vecql

Gives the q-vector in lattice coordinates for calculating ELNES.

Type:	vect3d
Default:	"0.0d0 0.0d0 0.0d0"
Use:	optional
XPath:	/input/properties/elnes/@vecql

Element: eliashberg

Type:	no content
XPath:	/input/properties/eliashberg

This element allows for specification of the following attributes:

Attribute: mustar

Coulomb pseudopotential, μ*, used in the McMillan-Allen-Dynes equation.

Type:	fortrandouble
Default:	"0.15d0"
Use:	optional
XPath:	/input/properties/eliashberg/@mustar

Element: phonons

Phonon frequencies and eigen vectors for an arbitrary q-point.

contains:	qpointset (optional) phonondos (optional) phonondispplot (optional) reformatdynmat (optional) interpolate (optional) parts (optional)
XPath:	/input/phonons

This element allows for specification of the following attributes:

Attribute: deltaph

Phonon calculations are performed by constructing a supercell corresponding to a particular ${\bf q}$ -vector and making a small periodic displacement of the atoms. The magnitude of this displacement is given by deltaph. This should not be made too large, as anharmonic terms could then become significant, neither should it be too small as this can introduce numerical error.

Type:	fortrandouble
Default:	"0.03d0"
Use:	optional
XPath:	/input/phonons/@deltaph

Attribute: do

Decides if the phonon calculation is skipped or recalculated or continued from file.

Type:	choose from: fromscratch skip
Default:	"fromscratch"
Use:	optional
XPath:	/input/phonons/@do

Attribute: ngridq

Number of q grid points along the basis vector directions.

Type:	integertriple
Use:	required
XPath:	/input/phonons/@ngridq

Attribute: reduceq

The attribute reduceq is set to "true" if the $q$ -point set is to be reduced with the crystal symmetries.

Type:	boolean
Default:	"true"
Use:	optional
XPath:	/input/phonons/@reduceq

Element: phonondos

Phonon density of states.

Type:	no content
XPath:	/input/phonons/phonondos

This element allows for specification of the following attributes:

Attribute: ngrdos

Type:	integer
Default:	"100"
Use:	optional
XPath:	/input/phonons/phonondos/@ngrdos

Attribute: nsmdos

Type:	integer
Default:	""
Use:	optional
XPath:	/input/phonons/phonondos/@nsmdos

Attribute: nwdos

Type:	integer
Default:	"500"
Use:	optional
XPath:	/input/phonons/phonondos/@nwdos

Element: phonondispplot

Phonon dispersion plot.

contains:	plot1d
XPath:	/input/phonons/phonondispplot

Element: reformatdynmat

Reads in the dynamical matrix rows from the corresponding files and outputs them in the DYNMAT*.OUT files, taking into account symmetrization and the accoustic sumrule.

Type:	no content
XPath:	/input/phonons/reformatdynmat

Element: interpolate

Interpolates the phonon frequencies on a given q-point set.

Type:	no content
XPath:	/input/phonons/interpolate

This element allows for specification of the following attributes:

Attribute: ngridq

q-point grid for interpolation.

Type:	integertriple
Use:	required
XPath:	/input/phonons/interpolate/@ngridq

Attribute: vqloff

The q-point offset vector in lattice coordinates.

Type:	vect3d
Default:	"0.0d0 0.0d0 0.0d0"
Use:	optional
XPath:	/input/phonons/interpolate/@vqloff

Attribute: writeeigenvectors

Set to true if the phonon eigenvectors are to be interpolated and output in addition to the phonon frequencies.

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/phonons/interpolate/@writeeigenvectors

Element: xs

If this element is present with valid configuration, the macroscopic dielectric function and related spectroscopic quantities in the linear regime are calculated through either time-dependent DFT (TDDFT) or the Bethe-Salpeter equation (BSE).

contains:	tddft (optional) screening (optional) BSE (optional) transitions (optional) qpointset (1 times) tetra (optional) energywindow (1 times) plan (optional)
XPath:	/input/xs

This element allows for specification of the following attributes:

Attribute: broad

Lorentzian broadening for all spectra

Type:	fortrandouble
Default:	"0.01d0"
Use:	optional
Unit:	Hartree
XPath:	/input/xs/@broad

Attribute: dbglev

debugging level

Type:	integer
Default:	""
Use:	optional
XPath:	/input/xs/@dbglev

Attribute: dfoffdiag

"true" if also off-diagonal tensor elements for the interacting response function are to be calculated

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/xs/@dfoffdiag

Attribute: emattype

Type of matrix element generation (band-combinations). Should only be referenced for experimental features.

Type:	integer
Default:	"1"
Use:	optional
XPath:	/input/xs/@emattype

Attribute: emaxdf

energy cutoff for the unoccupied states in the Kohn-Sahm response function and screening

Type:	fortrandouble
Default:	"1.0d10"
Use:	optional
XPath:	/input/xs/@emaxdf

Attribute: epsdfde

smallest energy difference for which the square of its inverse will be considered in the Kohn-Sham response function

Type:	fortrandouble
Default:	"1.0d-8"
Use:	optional
Unit:	Hartree
XPath:	/input/xs/@epsdfde

Attribute: fastemat

if "true" , a fast method to calculate APW-lo, lo-APW and lo-lo parts of the ${\bf q}$ -dependent matrix elements in the muffin-tin is used.

Type:	boolean
Default:	"true"
Use:	optional
XPath:	/input/xs/@fastemat

Attribute: fastpmat

if "true" , a fast method to calculate APW-lo, lo-APW and lo-lo parts of the momentum matrix elements in the muffin-tin is used.

Type:	boolean
Default:	"true"
Use:	optional
XPath:	/input/xs/@fastpmat

Attribute: gqmax

|G+q| cutoff for Kohn-Sham response function, screening and for expansion of Coulomb potential

Type:	fortrandouble
Default:	"0.0d0"
Use:	optional
XPath:	/input/xs/@gqmax

Attribute: gqmaxtype

Defines the way the gqmax cutoff is applied for the selection of the G-vectors

Type:	choose from: |G+q| |G|
Default:	"|G+q|"
Use:	optional
XPath:	/input/xs/@gqmaxtype

Attribute: lmaxapw

angular momentum cut-off for the APW functions

Type:	integer
Default:	"10"
Use:	optional
XPath:	/input/xs/@lmaxapw

Attribute: lmaxapwwf

maximum angular momentum for APW functions for q-dependent matrix elements

Type:	integer
Default:	"-1"
Use:	optional
XPath:	/input/xs/@lmaxapwwf

Attribute: lmaxemat

maximum angular momentum for Rayleigh expansion of ${\bf q}$ -dependent plane wave factor

Type:	integer
Default:	"3"
Use:	optional
XPath:	/input/xs/@lmaxemat

Attribute: lmaxmat

angular momentum cut-off for the outer-most loop in the hamiltonian and overlap matrix setup

Type:	integer
Default:	"5"
Use:	optional
XPath:	/input/xs/@lmaxmat

Attribute: nempty

Number of empty states. This parameter determines the energy cutoff for the excitation spectra. For determining the number of states realted to an energy cutoff, perform one iteration of a SCF calculation, setting nempty to a higher value and check the EIGVAL.OUT

Type:	integer
Default:	"5"
Use:	optional
XPath:	/input/xs/@nempty

Attribute: ngridk

k-point grid sizes

Type:	integertriple
Default:	"1 1 1"
Use:	optional
XPath:	/input/xs/@ngridk

Attribute: ngridq

q-point grid sizes

Type:	integertriple
Default:	"1 1 1"
Use:	optional
XPath:	/input/xs/@ngridq

Attribute: nosym

nosym is "true" if no symmetry information should be used

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/xs/@nosym

Attribute: reducek

reducek is "true" if k-points are to be reduced (with crystal symmetries)

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/xs/@reducek

Attribute: reduceq

reducek is "true" if q-points are to be reduced (with crystal symmetries)

Type:	boolean
Default:	"true"
Use:	optional
XPath:	/input/xs/@reduceq

Attribute: rgkmax

smallest muffin-tin radius times gkmax

Type:	fortrandouble
Default:	"7.0d0"
Use:	optional
XPath:	/input/xs/@rgkmax

Attribute: scissor

scissors correction

Type:	fortrandouble
Default:	"0.0d0"
Use:	optional
Unit:	Hartree
XPath:	/input/xs/@scissor

Attribute: swidth

width of the smooth approximation to the Dirac delta function (must be greater than zero)

Type:	fortrandouble
Default:	"0.001d0"
Use:	optional
Unit:	Hartree
XPath:	/input/xs/@swidth

Attribute: tappinfo

true if to append info to output file

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/xs/@tappinfo

Attribute: tevout

"true" if energy outputs are in eV

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/xs/@tevout

Attribute: vkloff

The k-point set offset. All k-points of a regular k-mesh (a mesh containing the Gamma point) are shifted by a constant vector given by $({\rm vkloff}_1/N_1, {\rm vkloff}_2/N_2, {\rm vkloff}_3/N_3)$ , where $(N_1,N_2,N_3)$ is the division of the k-point mesh. It should be selected such that all symmetries among the k-points from the regular (non-shifted) mesh are broken. An exception is the case of optical spectra without local field effects where symmetries among k-points are explicitly taken into account.

Type:	vect3d
Default:	"0.0d0 0.0d0 0.0d0 "
Use:	optional
XPath:	/input/xs/@vkloff

Attribute: xstype

Should TDDFT be used or BSE

Type:	choose from: TDDFT BSE
Use:	required
XPath:	/input/xs/@xstype

Element: tddft

Type:	no content
XPath:	/input/xs/tddft

This element allows for specification of the following attributes:

Attribute: acont

true if analytic continuation from the imaginary axis to the real axis is to be performed

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/xs/tddft/@acont

Attribute: alphalrc

alpha-parameter for the static long range contribution (LRC) model xc kernel

Type:	fortrandouble
Default:	"0.0d0"
Use:	optional
XPath:	/input/xs/tddft/@alphalrc

Attribute: alphalrcdyn

alpha-parameter for the dynamical long range contribution (LRC) model xc kernel

Type:	fortrandouble
Default:	"0.0d0"
Use:	optional
XPath:	/input/xs/tddft/@alphalrcdyn

Attribute: aresdf

Is "true" if to consider the anti-resonant part for the dielectric function

Type:	boolean
Default:	"true"
Use:	optional
XPath:	/input/xs/tddft/@aresdf

Attribute: aresfxc

Is "true" if to consider the anti-resonant part for the MBPT derived xc-kernels

Type:	boolean
Default:	"true"
Use:	optional
XPath:	/input/xs/tddft/@aresfxc

Attribute: betalrcdyn

beta-parameter for the dynamical long range contribution (LRC) model xc kernel

Type:	fortrandouble
Use:	optional
XPath:	/input/xs/tddft/@betalrcdyn

Attribute: do

Decides if the TDDFT calculation is to be resumed starting from a new xc kernel or is to be skipped.

Type:	choose from: fromscratch fromkernel
Default:	"fromscratch"
Use:	optional
XPath:	/input/xs/tddft/@do

Attribute: fxcbsesplit

Split parameter for degeneracy in energy differences of MBPT derived xc kernels

Type:	fortrandouble
Default:	"1.0d-5"
Use:	optional
Unit:	Hartree
XPath:	/input/xs/tddft/@fxcbsesplit

Attribute: fxctype

defines which xc kernel is to be used

Type:	choose from: RPA LRCstatic_NLF LRCstatic LRCdyn_NLF LRCdyn ALDA MB1_NLF MB1
Default:	"RPA"
Use:	optional
XPath:	/input/xs/tddft/@fxctype

Attribute: intraband

The intraband attribute is "true" if the intraband term is to be added to the optical matrix (q=0)

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/xs/tddft/@intraband

Attribute: kerndiag

"true" if only diagonal part of xc-kernel is used

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/xs/tddft/@kerndiag

Attribute: lindhard

"true" if Lindhard like function is calculated (trivial matrix elements)

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/xs/tddft/@lindhard

Attribute: lmaxalda

angular momentum cutoff for Rayleigh expansion of exponential factor for ALDA-kernel

Type:	integer
Default:	"3"
Use:	optional
XPath:	/input/xs/tddft/@lmaxalda

Attribute: mdfqtype

treatment of macroscopic dielectric function for ${\bf Q}$ -point outside of Brillouin zone. A value of 0 uses the full ${\bf Q}$ and and the $({\bf 0},{\bf 0})$ component of the microscopic dielectric matrix is used. A value of 1 invokes a decomposition ${\bf Q}={\bf q}+{\bf G}_{\bf q}$ and and the $({\bf Q}_{\bf q},{\bf Q}_{\bf q})$ component of the microscopic dielectric matrix is used.

Type:	integer
Default:	""
Use:	optional
XPath:	/input/xs/tddft/@mdfqtype

Attribute: nwacont

number of energy intervals (on imaginary axis) for analytic continuation

Type:	integer
Default:	""
Use:	optional
XPath:	/input/xs/tddft/@nwacont

Attribute: torddf

Is "true" if to consider the time-ordered version of the dielectric function

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/xs/tddft/@torddf

Attribute: tordfxc

Is "true" if to consider the time-ordered version of xc kernel (MBPT derived kernels only)

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/xs/tddft/@tordfxc

Element: screening

Type:	no content
XPath:	/input/xs/screening

This element allows for specification of the following attributes:

Attribute: do

Decides if the calculation of the screening is done from scratch or is to be skipped.

Type:	choose from: fromscratch skip
Default:	"fromscratch"
Use:	optional
XPath:	/input/xs/screening/@do

Attribute: nempty

number of empty states

Type:	integer
Default:	""
Use:	optional
XPath:	/input/xs/screening/@nempty

Attribute: ngridk

k-point grid sizes for screening

Type:	integertriple
Default:	"0 0 0"
Use:	optional
XPath:	/input/xs/screening/@ngridk

Attribute: nosym

nosym is "true" if no symmetry information should be used for screening

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/xs/screening/@nosym

Attribute: reducek

reducek is "true" if k-points are to be reduced (with crystal symmetries) for screening.

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/xs/screening/@reducek

Attribute: rgkmax

smallest muffin-tin radius times gkmax for screening

Type:	fortrandouble
Default:	"0.0d0"
Use:	optional
XPath:	/input/xs/screening/@rgkmax

Attribute: screentype

defines which screening is used

Type:	choose from: full diag noinvdiag longrange
Default:	"full"
Use:	optional
XPath:	/input/xs/screening/@screentype

Attribute: vkloff

k-point offset for screening

Type:	vect3d
Default:	"-1.0d0 -1.0d0 -1.0d0"
Use:	optional
XPath:	/input/xs/screening/@vkloff

Element: BSE

Type:	no content
XPath:	/input/xs/BSE

This element allows for specification of the following attributes:

Attribute: aresbse

Is "true" if to consider the anti-resonant part for the BSE spectrum

Type:	boolean
Default:	"true"
Use:	optional
XPath:	/input/xs/BSE/@aresbse

Attribute: bsedirsing

true if effective singular part of direct term of BSE Hamiltonian is to be used

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/xs/BSE/@bsedirsing

Attribute: bsetype

defines which parts of the BSE Hamiltonian are to be considered

Type:	choose from: IP RPA singlet triplet
Default:	"singlet"
Use:	optional
XPath:	/input/xs/BSE/@bsetype

Attribute: fbzq

true if q-point set is taken from first Brillouin zone

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/xs/BSE/@fbzq

Attribute: lmaxdielt

angular momentum cutoff of the spherical harmonics expansion of the dielectric matrix

Type:	integer
Default:	"14"
Use:	optional
XPath:	/input/xs/BSE/@lmaxdielt

Attribute: nexcitmax

maximum number of excitons to be considered in a BSE calculation

Type:	integer
Default:	"100"
Use:	optional
XPath:	/input/xs/BSE/@nexcitmax

Attribute: nleblaik

number of points used for the Lebedev-Laikov grids (must be selected according to Ref.LebLaik)

Type:	integer
Default:	"5810"
Use:	optional
XPath:	/input/xs/BSE/@nleblaik

Attribute: nosym

set to "true" if no symmetry information should be used for BSE.

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/xs/BSE/@nosym

Attribute: nstlbse

range of bands included for the BSE calculation. The first pair of numbers correspond to the band index for local orbitals and valence states (counted from the lowest eigenenergy), the second pair correspond to the band index of the conduction states (counted from the Fermi level)

Type:	integerquadrupel
Default:	"0 0 0 0"
Use:	optional
XPath:	/input/xs/BSE/@nstlbse

Attribute: nstlbsemat

range of bands for calculating the screening and matrix elements needed for solving BSE. The first pair of numbers correspond to the band index for local orbitals and valence states (counted from the lowest eigenenergy), the second pair correspond to the band index of the conduction states (counted from the Fermi level)

Type:	integerquadrupel
Default:	"0 0 0 0"
Use:	optional
XPath:	/input/xs/BSE/@nstlbsemat

Attribute: reducek

reducek is "true" if k-points are to be reduced (with crystal symmetries) for BSE.

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/xs/BSE/@reducek

Attribute: rgkmax

smallest muffin-tin radius times gkmax

Type:	fortrandouble
Default:	"0.0d0"
Use:	optional
XPath:	/input/xs/BSE/@rgkmax

Attribute: sciavbd

"true" if the body of the screened Coulomb interaction is to be averaged (q=0)

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/xs/BSE/@sciavbd

Attribute: sciavqbd

"true" if the body of the screened Coulomb interaction is to be averaged (q!=0)

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/xs/BSE/@sciavqbd

Attribute: sciavqhd

"true" if the head of the screened Coulomb interaction is to be averaged (q!=0)

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/xs/BSE/@sciavqhd

Attribute: sciavqwg

"true" if the wings of the screened Coulomb interaction is to be averaged (q!=0)

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/xs/BSE/@sciavqwg

Attribute: sciavtype

defines how the screened Coulomb interaction matrix is to be averaged (important for the singular terms)

Type:	choose from: spherical screendiag invscreendiag
Default:	"spherical"
Use:	optional
XPath:	/input/xs/BSE/@sciavtype

Attribute: scrherm

Method of how an almost Hermitian matrix is inverted. A value of 0: invert full matrix (matrix is allowed to be not strictly Hermitian); a value of 1: take the Hermitian average for inversion; a value of 2: assume Hermitian and use the upper triangle; a value of 3: assume Hermitian and use the lower triangle.

Type:	integer
Default:	""
Use:	optional
XPath:	/input/xs/BSE/@scrherm

Attribute: vkloff

k-point offset for BSE

Type:	vect3d
Default:	"-1.0d0 -1.0d0 -1.0d0"
Use:	optional
XPath:	/input/xs/BSE/@vkloff

Element: transitions

Describe transitions between Kohn-Sham states for the calculation of the Kohn-Sham response function (and screening) here. Individual transitions can be defined as well as a range (or a list) of initial and final states can be defined.

contains:	individual (optional) ranges (optional) lists (optional)
XPath:	/input/xs/transitions

Element: individual

A list of individual transitions consisting of an initial state a final state and a k-point is given here. An empty list amounts to no transitions at all.

contains:	trans (zero or more)
XPath:	/input/xs/transitions/individual

Element: trans

An individual transition consisting of an initial state a final state and a k-point is given here. Values of zero correspond to the inclusion of all initial and final states and all k-points and can be used as "wildcards" (default). Therefore, an empty element amounts to include all transitions.

Type:	no content
XPath:	/input/xs/transitions/individual/trans

This element allows for specification of the following attributes:

Attribute: action

Select to include or exclude states. If a state is included as well as excluded several times the last definition (in the sequence of individual transitions) counts.

Type:	choose from: include exclude
Default:	"include"
Use:	optional
XPath:	/input/xs/transitions/individual/trans/@action

Attribute: final

Final state of individual transition. A value of zero (default) means to include all states.

Type:	integer
Default:	""
Use:	optional
XPath:	/input/xs/transitions/individual/trans/@final

Attribute: initial

Initial state of individual transition. A value of zero (default) means to include all states.

Type:	integer
Default:	""
Use:	optional
XPath:	/input/xs/transitions/individual/trans/@initial

Attribute: kpointnumber

Number of k-point to consider. A value of zero (default) means to include all k-points.

Type:	integer
Default:	""
Use:	optional
XPath:	/input/xs/transitions/individual/trans/@kpointnumber

Element: ranges

A list of ranges of transitions (initial state as well as final state ranges) and a k-point are given here. An empty list amounts to no transitions at all.

contains:	range (zero or more)
XPath:	/input/xs/transitions/ranges

Element: range

A range of transitions (for initial as well as final states) is given here. A range consists of a "start" and a "stop" value as well as a k-point. Values of zero correspond to starting at the first state and stopping at the last state and considering all k-points. They can be used as "wildcards" (default). Therefore, an empty element corresponds to the full initial/final state range for all k-points.

Type:	no content
XPath:	/input/xs/transitions/ranges/range

This element allows for specification of the following attributes:

Attribute: action

Select to include or exclude states. If a state is included as well as excluded several times the last definition (in the sequence of individual transitions) counts.

Type:	choose from: include exclude
Default:	"include"
Use:	optional
XPath:	/input/xs/transitions/ranges/range/@action

Attribute: kpointnumber

Number of k-point to consider. A value of zero (default) means to include all k-point.

Type:	integer
Default:	""
Use:	optional
XPath:	/input/xs/transitions/ranges/range/@kpointnumber

Attribute: start

Start value (first state) for range. A value of zero (default) means to start from the first state.

Type:	integer
Default:	""
Use:	optional
XPath:	/input/xs/transitions/ranges/range/@start

Attribute: statestype

Select for initial or final state range

Type:	choose from: initialstates finalstates
Use:	required
XPath:	/input/xs/transitions/ranges/range/@statestype

Attribute: stop

Stop value (last state) for range. A value of zero (default) means to stop at the last state (no upper limit).

Type:	integer
Default:	""
Use:	optional
XPath:	/input/xs/transitions/ranges/range/@stop

Element: lists

A list of initial and final state entries to be considered for transitions. An empty list amounts to no transitions at all.

contains:	istate (zero or more)
XPath:	/input/xs/transitions/lists

Element: istate

An initial or final state and corresponding k-point is given here. Values of zero correspond to considering all initial/final states for all k-points. They can be used as "wildcards" (default). Therefore, an empty element corresponds to the full initial/final state set for all k-points.

Type:	no content
XPath:	/input/xs/transitions/lists/istate

This element allows for specification of the following attributes:

Attribute: action

Select to include or exclude states. If a state is included as well as excluded several times the last definition (in the sequence of individual transitions) counts.

Type:	choose from: include exclude
Default:	"include"
Use:	optional
XPath:	/input/xs/transitions/lists/istate/@action

Attribute: kpointnumber

Number of k-point to consider. A value of zero (default) means to include all k-point.

Type:	integer
Default:	""
Use:	optional
XPath:	/input/xs/transitions/lists/istate/@kpointnumber

Attribute: state

The state to be considered. A value of zero (default) means to include all states.

Type:	integer
Default:	""
Use:	optional
XPath:	/input/xs/transitions/lists/istate/@state

Attribute: statestype

Select for initial or final state list

Type:	choose from: initialstates finalstates
Use:	required
XPath:	/input/xs/transitions/lists/istate/@statestype

Element: tetra

Type:	no content
XPath:	/input/xs/tetra

This element allows for specification of the following attributes:

Attribute: cw1k

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/xs/tetra/@cw1k

Attribute: kordexc

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/xs/tetra/@kordexc

Attribute: qweights

choice of weights and nodes for tetrahedron method and non-zero Q-point

Type:	integer
Default:	"1"
Use:	optional
XPath:	/input/xs/tetra/@qweights

Attribute: tetradf

"true" if tetrahedron method is used for the k-space integration in the Kohn-Sham response function

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/xs/tetra/@tetradf

Attribute: tetraocc

Type:	boolean
Default:	"false"
Use:	optional
XPath:	/input/xs/tetra/@tetraocc

Element: plan

contains:	doonly (zero or more)
XPath:	/input/xs/plan

Element: doonly

Type:	no content
XPath:	/input/xs/plan/doonly

This element allows for specification of the following attributes:

Attribute: task

Type:	choose from: xsgeneigvec tetcalccw writepmatxs writeemat df df2 idf scrgeneigvec scrtetcalccw scrwritepmat screen scrcoulint exccoulint bse kernxc_bse writebandgapgrid writepmat dielectric writepmatasc pmatxs2orig writeematasc writepwmat emattest x0toasc x0tobin fxc_alda_check kernxc_bse3 testxs xsestimate xstiming testmain portstate(1) portstate(2) portstate(-1) portstate(-2)
Use:	required
XPath:	/input/xs/plan/doonly/@task

Element: keywords

The keywords tag can contain a space separated list of keywords classifying the calculation for archiving purposes. It is not used by the exciting program.

Type:	string
XPath:	/input/keywords

Reused Elements

The following elements can occur more than once in the input file. There for they are listed separately.

Element: origin

Type:	no content
XPath:	./origin
Parent:	./plot2d/parallelogram ./plot3d/box

This element allows for specification of the following attributes:

Attribute: coord

Type:	vect3d
Use:	optional
XPath:	./origin/@coord

Element: point

Type:	no content
XPath:	./point
Parent:	./plot1d/path ./plot2d/parallelogram ./plot3d/box

This element allows for specification of the following attributes:

Attribute: coord

Type:	vect3d
Use:	required
XPath:	./point/@coord

Attribute: label

Type:	string
Default:	""
Use:	optional
XPath:	./point/@label

Element: plot1d

The element plot1d specifies sample points along a path. The coordinate space (lattice or cartesian)is chosen in the context of the parent.

contains:	path (1 times)
XPath:	./plot1d
Parent:	/input/properties/bandstructure /input/properties/wfplot /input/properties/chargedensityplot /input/properties/exccplot /input/properties/elfplot /input/properties/gradmvecfield /input/phonons/phonondispplot

Element: path

contains:	point (2 times or more)
XPath:	./plot1d/path

This element allows for specification of the following attributes:

Attribute: outfileprefix

Type:	string
Use:	optional
XPath:	./plot1d/path/@outfileprefix

Attribute: steps

Type:	integer
Use:	required
XPath:	./plot1d/path/@steps

Element: plot2d

Defines a 2d plot domain.

contains:	parallelogram (1 times)
XPath:	./plot2d
Parent:	/input/properties/STM /input/properties/wfplot /input/properties/chargedensityplot /input/properties/exccplot /input/properties/elfplot /input/properties/mvecfield /input/properties/xcmvecfield /input/properties/electricfield /input/properties/gradmvecfield

Element: parallelogram

contains:	origin (1 times) point (2 times)
XPath:	./plot2d/parallelogram

This element allows for specification of the following attributes:

Attribute: grid

Type:	integerpair
Use:	required
XPath:	./plot2d/parallelogram/@grid

Attribute: outfileprefix

Type:	string
Use:	optional
XPath:	./plot2d/parallelogram/@outfileprefix

Element: plot3d

Defines a 3d plot domain.

contains:	box (1 times)
XPath:	./plot3d
Parent:	/input/properties/wfplot /input/properties/chargedensityplot /input/properties/exccplot /input/properties/elfplot /input/properties/mvecfield /input/properties/xcmvecfield /input/properties/electricfield /input/properties/gradmvecfield

Element: box

contains:	origin (1 times) point (3 times)
XPath:	./plot3d/box

This element allows for specification of the following attributes:

Attribute: grid

Type:	integertriple
Use:	required
XPath:	./plot3d/box/@grid

Attribute: outfileprefix

Type:	string
Use:	optional
XPath:	./plot3d/box/@outfileprefix

Element: pointstatepair

The element pointstatepair defines a ${ \bf k}$ -point and state index pair.

Type:	integerpair
XPath:	./pointstatepair
Parent:	./kstlist

Element: kstlist

The kstlist element is used in the LSJ and wavefunction plot element This is a user-defined list of ${ \bf k}$ -point and state index pairs which are those used for plotting wavefunctions and writing ${ \bf L}$ , ${ \bf S}$ and ${ \bf J}$ expectation values.

contains:	pointstatepair (1 times or more)
XPath:	./kstlist
Parent:	/input/properties/wfplot /input/properties/LSJ

Element: energywindow

Type:	no content
XPath:	./energywindow
Parent:	/input/xs

This element allows for specification of the following attributes:

Attribute: intv

energy interval lower and upper limits.

Type:	vect2d
Default:	"-0.5d0 0.5d0"
Use:	optional
XPath:	./energywindow/@intv

Attribute: points

number of points to be sampled linearly inside the energy interval including the lower limit.

Type:	integer
Default:	"500"
Use:	optional
XPath:	./energywindow/@points

Element: qpointset

contains:	qpoint (1 times or more)
XPath:	./qpointset
Parent:	/input/phonons /input/xs

Element: qpoint

a q-point is given in reciprocal space coordinates

Type:	vect3d
XPath:	./qpointset/qpoint

Element: parts

contains:	dopart (zero or more)
XPath:	./parts
Parent:	/input/phonons

Element: dopart

Type:	no content
XPath:	./parts/dopart

This element allows for specification of the following attributes:

Attribute: id

This attribute is used to trigger lower-level tasks and is mainly used for testing, debugging, and the testing of new features. Do not use it unless you know what you are doing.

Type:	string
Use:	required
XPath:	./parts/dopart/@id

Data Types

The Input definition uses derived data types. These are described here.

Type fortrandouble

The type fortrandouble allows to use the letters "eEdDqQ" for exponent operators. This alters in what precision the number is parsed.

Type vector

A vector is a space separated list of floating point numbers.

Example: "1.3 2.3e4 3 90"

Type integerlist

List of space separated integers.

Type vect3d

Three dimensional vector as three space separated floating point numbers.

Type vect2d

Three dimensional vector as three space separated floating point numbers.

Type integertriple

Space separated list of three integers.

Example: "1 2 3"

Type integerquadrupel

Space separated list of three integers.

Example: "1 2 3 4"

Type integerpair

Space separated list of two integers

Example: "1 2"