General information
- materials can be defined via files specifying unit cell
- file extension is expected to be .cell
- by default, the files are saved in subdirectory fzuCommon/cellData/unitCells of the directory, where the CrysTBox is installed to
- file name should reflect file content
- comments are denoted by '#' or '%'
- white characters between lines or individual numbers are ommited
Data
The CELL files require the unit cell properties to be stated in the following order:
- lattice parameter a [nm]
- lattice parameter b [nm]
- lattice parameter c [nm]
- lattice angle alpha [deg]
- lattice angle beta [deg]
- lattice angle gamma [deg]
- material structure ('HCP', 'FCC', 'BCC', Diamond') or by fractional Miller indices of individual atoms in the unit cell written as decimal numbers or fractions
- in case of Miller indices, one atom must have coordinates [0 0 0]
- if there is no atom in [0 0 0] coordinates, all atoms are automatically shifted to fulfill this condition
- atomic numbers - either one number if they are all the same for unit cell atoms, or space-separated values - one per each previously stated atom
Examples
File 'Mg HCP.cell' describing Mg HCP unit cell:
# Mg HCP
# Lattice parameters - a, b, c [nm]
0.321
0.321
0.521
# Lattice angles - alpha, beta, gamma [deg]
90
90
120
# Structure
HCP
# Element
12
File 'GaAs.cell' describing unit cell of GaAs compound:
# Lattice parameters - a, b, c [nm]
0.565
0.565
0.565
# Lattice angles - alpha, beta, gamma [deg]
90
90
90
# Positions of atoms in unit cell
[0 0 0]
[0 1/2 1/2]
[1/2 0 1/2]
[1/2 1/2 0]
[1/4 1/4 1/4]
[3/4 3/4 1/4]
[1/4 3/4 3/4]
[3/4 1/4 3/4]
# Element
31 31 31 31 33 33 33 33