triqs.operators.util.U_matrix.eg_submatrix

triqs.operators.util.U_matrix.eg_submatrix(U, convention='triqs')

Extract the eg submatrix of the full d-manifold two- or four-index U matrix.

Parameters:

• U (float numpy array) – Two- or four-index interaction matrix.

• 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:

U_eg – The eg component of the interaction matrix.

Return type:

float numpy array