Theoretical spectroscopy on K–2, K–1L–1, and L–2 double core hole states of SiX 4 (X = H, F, Cl, and CH 3) molecules

Abstract

We have investigated the K –2, K –1 L –1, and L –2 double core hole (DCH) states of the SiX 4 (X = H, F, Cl, and CH 3) molecules using the CASSCF and DFT methods aiming at the DCH electron spectroscopy. The Si 1 s IPs and DIPs of the present molecules and the generalized relaxation energies are compared and analyzed. The values extracted from the excess relaxation energy agree well with the generalized relaxation energy. The effect of the substituents (H, F, Cl, and CH 3) surrounding the central Si atom is examined. The present results illustrate that the DCH electron spectroscopy for K –2, K –1 L –1, and L –2 DCH states is useful for the chemical analysis.