Element: symmetries
The symmetries file format used by the spacegroup tool to generate structures and supercells as defined by lattice from the knowledge of Wyckoff positions and the space group. The space group is specified by the attribute HermannMauguinSymbol. The root element is symmetries.
contains: | title (required) lattice (required) WyckoffPositions (optional) |
XPath: | ./symmetries |
This element allows for specification of the following attributes: HermannMauguinSymbol (required)
Attribute: HermannMauguinSymbol
The Herman Mauguin symbol specifies the spacegroup of the structure. The table of all the symbols lists all possible inputs.
Type: | string |
Use: | required |
XPath: | ./symmetries/@HermannMauguinSymbol |
Element: title
Type: | string |
XPath: | ./symmetries/title |
Element: lattice
The lattice element defines lattice from a,b,c, and angles.
Type: | no content |
XPath: | ./symmetries/lattice |
This element allows for specification of the following attributes: a (required), ab (required), ac (required), b (required), bc (required), c (required), epslat, ncell, primcell, scale, speciespath, stretch
Attribute: a
Type: | fortrandouble |
Use: | required |
Unit: | Bohr |
XPath: | ./symmetries/lattice/@a |
Attribute: ab
Angle between lattice vector a and b in degrees.
Type: | fortrandouble |
Use: | required |
Unit: | Degree |
XPath: | ./symmetries/lattice/@ab |
Attribute: ac
Angle between lattice vector a and c in degrees.
Type: | fortrandouble |
Use: | required |
Unit: | Degree |
XPath: | ./symmetries/lattice/@ac |
Attribute: b
Type: | fortrandouble |
Use: | required |
Unit: | Bohr |
XPath: | ./symmetries/lattice/@b |
Attribute: bc
Angle between lattice vector b and c in degrees.
Type: | fortrandouble |
Use: | required |
Unit: | Degree |
XPath: | ./symmetries/lattice/@bc |
Attribute: c
Type: | fortrandouble |
Use: | required |
Unit: | Bohr |
XPath: | ./symmetries/lattice/@c |
Attribute: epslat
Type: | fortrandouble |
Default: | "1.0d-6" |
Use: | optional |
XPath: | ./symmetries/lattice/@epslat |
Attribute: ncell
Number of repeated cells in each direction.
Type: | integertriple |
Default: | "1 1 1" |
Use: | optional |
XPath: | ./symmetries/lattice/@ncell |
Attribute: primcell
Type: | boolean |
Default: | "false" |
Use: | optional |
XPath: | ./symmetries/lattice/@primcell |
Attribute: scale
Scales all the lattice vectors by the same factor. This is useful for varying the volume.
Type: | fortrandouble |
Default: | "1" |
Use: | optional |
XPath: | ./symmetries/lattice/@scale |
Attribute: speciespath
Type: | string |
Default: | "http://xml.exciting-code.org/species/" |
Use: | optional |
XPath: | ./symmetries/lattice/@speciespath |
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: | ./symmetries/lattice/@stretch |
Element: WyckoffPositions
contains: | wspecies (optional) |
XPath: | ./symmetries/WyckoffPositions |
Element: wspecies
contains: | wpos (optional) |
XPath: | ./symmetries/WyckoffPositions/wspecies |
This element allows for specification of the following attributes: speciesfile
Attribute: speciesfile
Type: | string |
Use: | optional |
XPath: | ./symmetries/WyckoffPositions/wspecies/@speciesfile |
Element: wpos
Type: | no content |
XPath: | ./symmetries/WyckoffPositions/wspecies/wpos |
This element allows for specification of the following attributes: coord
Attribute: coord
Type: | vect3d |
Use: | optional |
XPath: | ./symmetries/WyckoffPositions/wspecies/wpos/@coord |
Reused Elements
The following elements can occur more than once in the input file. There for they are listed separately.
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 booleanlist
List of space separated booleans.
Type booleantriple
Space separated list of three booleans.
Type vector
A vector is a space separated list of floating point numbers.
Type integerlist
List of space separated integers.
Type vect3d
Three dimensional vector as three space separated floating point numbers.
Type vect2d
Two dimensional vector as two space separated floating point numbers.
Type integertriple
Space separated list of three integers.
Type integerquadrupel
Space separated list of three integers.
Type integerpair
Space separated list of two integers
Example: "1 2"