Influence of chemical environment on resonant core excitation of C(1s) in CO2, OCS, and CS2 by electron impact

In this work, we report a theoretical study of the role played by chemical environment on the electron-impact resonant core excitations in OCS, CO2, and CS2 molecules. Calculated differential and integral cross sections for the promotion of a carbon 1s electron to the lowest unfilled pπ orbital of these molecules, or more specifically, the ratios of these cross sections for the corresponding transitions leading to the singlet and the triplet core-excited states in the 300-800 eV incident energy range, are reported. The distorted-wave approximation was applied to these calculations. Our study revealed resonance structures in the calculated ratios for CO2, in good agreement with the available experimental observation, which is very encouraging. On the other hand, no resonance structure is clearly seen in the calculated ratios for OCS and CS2 molecules. The possible reason for the nonappearance of resonance for these two targets is discussed