SPHERICAL CHARGE ANALYSIS WITH AB-INITIO WAVE-FUNCTIONS - MODIFIED OXIDATION NUMBER OF OPEN-SHELL MOLECULE, CH2

Spherical charge analysis based on the difference of spherically avera ged electron density (Delta rho(0)(R)) was extended to various open sh ell states of CH2 using wave functions obtained from RHF, UHF, and ful l CI calculations. The Delta rho(0)(R) values around C and H atoms wer e calculated with natural orbitals to interpret the oxidation state of component atoms for the lowest and second lowest B-3(1) and (1)A(1) s tates. Modified oxidation numbers are assigned systematically to the c omponent atoms in CH2 based on the extended Delta rho(0)(R) analysis. The effect of electron correlation on the Delta rho(0)(R) values aroun d the nucleus in this system was found to be so small that the modifie d oxidation numbers are not changed by fair introduction of electron c orrelation effect into the calculation. The difference of spin multipl icity and state symmetry on the Delta rho(0)(R) curves is also discuss ed.