Double core excitation at the sulfur K edge in H 2S, SO 2 and SF 6

Abstract

We report an experimental and theoretical study of the double-core excitation processes in some sulfurcontainging molecules in the gas phase. Absolute X-ray absorption cross-section of H 2S, SO 2 and SF 6 have been measured in the 2400–2800 eV region. Several narrow features are observed some 200 eV above the edge and assigned to 1s2p double core excited states. The spectra depend upon atomic effects but also on the bonding partner of the sulfur atom. The detailed assignment of resonances of H 2S is made using calculations performed on the Z+2 core equivalent species ArH 2 and can be understood by analogy with the excited states of the ArH + H system. Interpretation of the SO 2 and SF 6 spectra are made by combining atomic and molecular effects.