Difinition of E2=0 for RIXS_L23M1

Dear developers,

I’d like to ask you the definition of E2=0 for L23M1 RIXS.

I’ve been trying to calculate RIXS L23M1 spectra to understand my experimental spectra of various 3d transition metals in Td symmetry (3d-TMs in semiconductors). I understand E2 for L23M45 RIXS, simple energy shift, thus I see elastic signals for L23M45 RIXS at E2=0.

Best regards,

Saki