X-ray spectroscopy at the MnK edge in LaMnO3:: An ab initio study -: art. no. 165104

We present ab initio quantum chemical embedded cluster calculations of Mn core-valence and d-d transitions in LaMnO3. The results are also important for the analysis of recent x-ray absorption and x-ray scattering experiments at the Mn K edge in LaMnO3. We find that the first two peaks of the pre-edge region correspond to majority-spin and minority-spin e(g)(3d) states on adjacent Mn ions. For on-site 1s to 4p transitions we find that the ordering of the p components is due to the Jahn-Teller distortion. We also show that the 1s --> 4p transitions are split due to 3d-4p exchange interactions.