Module: xrd.symmetry

4 Functions

hexrd.xrd.symmetry.toFundamentalRegion(q, crysSym='Oh', sampSym=None)

hexrd.xrd.symmetry.ltypeOfLaueGroup(tag)

See quatOfLaueGroup

hexrd.xrd.symmetry.quatOfLaueGroup(tag)

Generate quaternion representation for the specified Laue group.

USAGE:

qsym = quatOfLaueGroup(schoenfliesTag)

INPUTS:

1) schoenfliesTag 1 x 1, a case-insensitive string representing the Schoenflies symbol for the desired Laue group. The 14 available choices are:

Class Symbol n

Triclinic Ci (S2) 1 Monoclinic C2h 2 Orthorhombic D2h (Vh) 4 Tetragonal C4h 4

D4h 8

Trigonal C3i (S6) 3

D3d 6

Hexagonal C6h 6

D6h 12

Cubic Th 12

Oh 24

OUTPUTS:

1) qsym is (4, n) the quaterions associated with each element of the chosen symmetry group having n elements (dep. on group – see INPUTS list above).

NOTES:

*) The conventions used for assigning a RHON basis, {x1, x2, x3}, to each point group are consistent with those published in Appendix B of [1].

REFERENCES:

[1] Nye, J. F., ``Physical Properties of Crystals: Their Representation by Tensors and Matrices’‘, Oxford University Press, 1985. ISBN 0198511655

hexrd.xrd.symmetry.applySym(vec, qsym, csFlag=False, cullPM=False, tol=1e-08)

apply symmetry group to a single 3-vector (columnar) argument

csFlag : centrosymmetry flag cullPM : cull +/- flag