As we know, to calculate the XAS of core-level orbital, we need to change the orbital from core-orbital
to local orbital. But if the target orbital is quite deep, and there are higher energy orbitals which are also
core-orbital by default, for example, if we want to calculate the L23-edge of Ce atom, besides the
2p orbitals, there are 3s, 3p, 3d, 4s, 4p and 4d orbitals that are also core-orbital by default.
Do we need to change all these orbital to local orbitals, rather than just change the orbitla we want to excite ?
Thanks for any help!