Multiple-scatteringXαstudy of the silicon and chlorine core-level photoabsorption spectra ofSiCl4

The Si 1s, 2s, 2p, and Cl 1s, 2p photoabsorption spectra of ${\mathrm{SiCl}}_4$ have been assigned with the aid of multiple-scattering Xα calculations. The strongest pre-edge absorptions are assigned to transitions to Si-Cl antibonding orbitals. The weaker complex features observed near the ionization threshold can be ascribed to electronic excitations into Rydberg orbitals. The calculations also show that the weak structures beyond the Si absorption edge are mainly due to resonances in the $e^{\mathrm{*}}$ and $t_2^{\mathrm{*}}$ continuum channels. Eigenphase sums indicate that the high-energy (≥20 eV) above-edge resonances are due to photoelectron diffraction.