Ab initio charge transfer multiplet calculations on the L2,3 XANES and ELNES of 3d transition metal oxides

The L-2,L-3 x-ray absorption near-edge structures (XANES) and electron energy loss near-edge structures (ELNES) of 3d transition metal (TM) oxides are systematically calculated by the ab initio charge transfer multiplet (CTM) method using fully relativistic molecular spinors on the basis of density-functional theory. The electronic excitation from molecular spinors mainly composed of O-2p to those of TM-3d, that is, charge transfer, is included by considering additional electronic configurations in the configuration interactions. The effects of the covalency and charge transfer on the TM-L-2,L-3 XANES are investigated in detail. The power of the ab initio CTM method to quantitatively reproduce the spectra is demonstrated. Meanwhile, limitations of the application of the method are discussed.