Theoretical study of the Cl 1s and 2p near edge photoabsorption spectra of HCl by accurate ab-initio configuration interaction and density functional approaches

摘要: Abstract Calculations of the discrete Cl 1s and 2p excitation spectra HCl are performed employing accurate ab-initio Configuration Interaction (CI) Density Functional (DF) approaches. The core excited above edge described with a new DF method based on one-centre approximation. highly correlated quasi-degenerate perturbation scheme gives results in excellent accord experimental data allows definite assignment Rydberg states below edge. simpler 1h–1p CI shows some deficiencies essentially attributed to use inadequate orbitals, although it appears adequate for qualitative description spectra. approach provides dependable lower-energy while limitations affect present higher states. Good agreement is obtained calculated cross-section profiles relative photoionization. Also theoretical asymmetry parameter analysed.