Many‐Electron Theory of Atoms and Molecules. V. First‐Row Atoms and Their Ions

Articles you may be interested in Proof of a fundamental theorem in the many‐electron theory for atoms and molecules The correlation energies of the 1S22s2 inner cores of the first-row atoms B, C. "', Ne are found to be very different from those of the corresponding four-electron Be-like ions, B+ to Ne6+, due to the exclusion effects of the outer 2p electrons. Whereas the 2S2 correlation, E (2s2) , in the 1s22s 2 ions increases from-1.13 e V in Be to-3.2 eV in Ne6+, the 2s2 correlation in the neutral atoms decreases from-1.13 eV in Be to-0.27 eV in Ne. The many-electron theory was used for the nonempirical2s 2 calculations and included the use of the 1'12 coordinate. With these theoretical E (2s 2) values the correlation of a 2p electron with the 1s22s2 inner core is found to be large, "-'-1 eV. Also the 2p2 correlation comes out about-1 e V. The results show that core energies will, in general, depend strongly on the state and number of the outer-shell electrons and that intershell correlation interactions may be appreciable. Implications for ...-electron systems and the ligand-field theory of inorganic complexes are discussed.