The spacegroup program takes a crystal definition as input and generates all the atom positions for the unit cell or if wanted supercell. In the spacegroup input one defines the space group by providing the Hermann Mauguin symbol and gives the Wyckoff positions of the atoms. spacegroup then applies the symmetry operations and gives back all the atom positions in the unit cell.
The input file format of spacegroup is the same as the exciting input format. spacegroup looks for a symmetry element in the structure definition and writes out the complete structure element to geometry.xml.
The output can be copied into an exciting input.xml file or used as starting point for a new input.xml in its own. spacegroup will accept its own output as input again.
Example input for spacegroup:
<input xsi:noNamespaceSchemaLocation="../../xml/excitinginput.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsltpath="../../xml/"> <title>Spacegroup Example</title> <structure speciespath=""> <symmetries HermannMauguinSymbol="Bmab"> <lattice a="10.0605232" b="10.0605232" c="24.972729" ab="90" ac="90" bc="90" ncell="1 1 1" /> <WyckoffPositions> <wspecies speciesfile="La.in"> <wpos coord="0.0000 0.0000 0.3608 " /> </wspecies> <wspecies speciesfile="Cu.in"> <wpos coord=" 0.0000 0.0000 0.0000" /> </wspecies> <wspecies speciesfile="O.in"> <wpos coord="0.2500 0.2500 0.0000" /> <wpos coord=" 0.0000 0.0000 0.1820" /> </wspecies> </WyckoffPositions> </symmetries> </structure> </input>
