An extended scheme for calculation of atomic charges by the modified Sanderson method and application to some polycyclic organic molecules

It has been demonstrated that the modified Sanderson formalism (MS) for calculation of atomic charge yields good correlation with C 1s core level shifts in organic molecules with carbon in the sp<SUP>3</SUP> hybridized state (Sastry, J. Electron. Spectrosc., 85 (1997) 167) as well as in monocyclic aromatic molecules (Patil et al., J. Electron Spectrosc., 85 (1997) 249). In this communication, a reinterpretation of the MS method is presented which leads to an extension of the scheme enabling application to polycyclic molecules for the first time. A linear relationship is established between partial charges on carbon and C 1s core level shifts in some polycyclic organic molecules