SYMMETRY_OPS (.cell)

Keyword type

Block

Description

This data block contains the symmetry operations under which the unit cell is invariant. Each operation is represented by a 3 × 3 array. The data block has the following format:

%BLOCK SYMMETRY_OPS
	R11        R21        R31
	R12        R22        R32
	R13        R23        R33
	T1         T2         T3
	R11        R21        R31
	R12        R22        R32
	R13        R23        R33
	T1         T2         T3
	.
	.
	.
%ENDBLOCK SYMMETRY_OPS

Each of the first three lines contains 3 entries representing a row of a 3 × 3 array. These represent one symmetry rotation. The three entries on the following line contain the translation associated with this rotation.

If no symmetry is specified in the cell definition file, the default is for no symmetry to be applied.

Example

%BLOCK SYMMETRY_OPS
	.
	.
	.
   -1.0000000000    0.0000000000    0.0000000000
    0.0000000000   -1.0000000000    0.0000000000
    0.0000000000    0.0000000000    1.0000000000
    0.5000000000    0.0000000000    0.5000000000
	.
	.
	.
%ENDBLOCK SYMMETRY_OPS

See Also:

CASTEP keyword glossary
CASTEP cell keywords and data blocks