Core Level Spectroscopy of Solids presents the theoretical calculations, experimental data, and underlying physics of x-ray photoemission spectroscopy (XPS), x-ray absorption spectroscopy (XAS), x-ray magnetic circular dichroism (XMCD), and resonant x-ray emission spectroscopy (RXES). After forming a foundation in several areas of core level spectroscopy, the book discusses hard XPS, resonant photoemission, spin polarization, electron energy loss spectroscopy (EELS), and resonant inelastic x-ray scattering (RIXS). The authors also use the charge transfer multiplet theory to interpret core level spectroscopy for transition metal and rare earth metal systems.