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Properties used to define the size of the simulation cell, spece group symmetry and use of PBC.

Unit Cell and Space Group Properties

Property Type Default Description
a-axis double none Length of the a-axis of the unit cell in Angstroms. There is no default for a-axis. If it is not specified, the calculation is treated as aperiodic.
b-axis double a-axis Length of the b-axis of the unit cell in Angstroms.
c-axis double a-axis Length of the c-axis of the unit cell in Angstroms.
alpha double 90.0 Angle between the b-axis and c-axis of the unit cell in degrees.
beta double 90.0 Angle between the a-axis and c-axis of the unit cell in degrees.
gamma double 90.0 Angle between the a-axis and b-axis of the unit cell in degrees.
spacegroup string P 1 One of the 230 space groups using the convention followed by the PDB CRYST1 record, which is to use a Hermann-Mauguin symbol without parenthesis, e.g., P 21 21 2 and using the full symbol, e.g., C 1 2 1 instead of C 2. The defaut is P 1 if an a-axis is specified, but not a space group. Internal checks are performed to ensure unit cell parameters are consistent with the symmetry of the space group.