Critical appraisal of the semiempirical wavefunctions by calculating ESCA chemical shifts: inner-shell binding energies in halogen atoms

• Published in: Journal of molecular structure. Theochem 1994-02, Vol.304 (2), p.163-171
• Main Authors: KOVACEK, D, KOVACEVIC, K, KORENIC, D, MAKSIC, Z. B
• Format: Article
• Language: English
• Subjects: Atomic and molecular physics; Electronic structure of atoms, molecules and their ions: theory; Exact sciences and technology; Other topics in the theory of the electronic structure of atoms, molecules and their ions; Physics
• ISSN: 0166-1280; 1872-7999
• DOI: 10.1016/S0166-1280(96)80008-X

Semiempirical F(1s), Cl(2s), Cl(2p 3 2 ), Br(3d 5 2 ) and I(3d 5 2 ) electron spectroscopy for chemical analysis (ESCA) chemical shifts obtained by using the SCC-MO, AMI and PM3 methods are presented and compared with the experimental data. Agreement with experiment for fluorine and chlorine inner-core binding energy shifts is good, being particularly satisfactory for Cl(2s) electrons. It is concluded that atomic charge distributions in molecules involving highly electronegative fluorine and chlorine atoms are fairly well described by the examined semiempirical approaches. However, Br(3d 5 2 ) and I(3d 5 2 ) ESCA shifts are less successfully reproduced by the semiempirical models. The origins of the corresponding discrepancies are briefly discussed. The use of ESCA shift in the parameterization of semiempirical methods is recommended.