triqs.operators.util.U_matrix.spherical_to_cubic

triqs.operators.util.U_matrix.spherical_to_cubic(l, convention='triqs')

Get the spherical harmonics to cubic harmonics transformation matrix.

Parameters:

• l (integer) – Angular momentum of shell being treated (l=2 for d shell, l=3 for f shell).

• convention (string, optional) –

  The basis convention. Takes the values

  • ’triqs’: basis ordered as (“xy”,”yz”,”z^2”,”xz”,”x^2-y^2”),

  • ’vasp’: same as ‘triqs’,

  • ’wien2k’: basis ordered as (“z^2”,”x^2-y^2”,”xy”,”yz”,”xz”),

  • ’wannier90’: basis order as (“z^2”, “xz”, “yz”, “x^2-y^2”, “xy”),

  • ’qe’: same as ‘wannier90’.

Returns:

T – Transformation matrix for basis change.

Return type:

real/complex numpy array