Syntax

[m, asym] = sw_basismat(symop, r, tol)

Description

[m, asym] = sw_basismat(symop, r, tol) determines the allowed tensor elements compatible with a given point group symmetry. The tensor can describe exchange interaction or single ion anisotropy. The function applies the symmetry invariance of the classical energy . Thus this symmetry analysis includes the transformation properties of spin operators as well.

Input Arguments

symOp
Generators of the point group symmetry, in a matrix with dimensions of where each symOp(:,:,ii) matrix defines a rotation.
r
Distance column vector between the two interacting atoms. For anisotropy .
tol
Tolerance, optional, default value is .

Output Arguments

M
Matrices, that span out the vector space of the symmetry allowed matrices, dimensions are . Any matrix is allowed that can be expressed as a linear combination of the symmetry allowed matrices.
asym
Logical vector, for each matrix in , tells whether it is antisymmetric stored in a row vector with elements.

See Also

spinw.getmatrix | spinw.setmatrix