Best method for non-resonant XES

I assume that the experiment you do is to excite a core electron into the vacuum with an x-ray and then have an other core or valence electron decay into the before created core state and emitting an x-ray photon. This is a two photon process and as such one needs the function CreateResonantSpectra. As you do not want to include the free electron states in your basis and you probably make the approximation that the emitted electron does not interact with the system you can use as the first transitions operator the annihilation of a core electron. The second operator then is the normal dipole operator. We'll make an example for NiO and add it to the tutorials, but that might take a little.

Best wishes, Maurits

I believe I may have been overthinking my original approach to the problem. I was more looking to calculate just the standard Kalpha XES spectra of a few 3d transition metals. I managed to do it by using the conjugate transpose of the 1s to 2p dipole transition operator and the “CreateSpectra” operator.