Theoretical study of the dissociative process of the 4-chlorotoluene radical anion

摘要: Abstract The dissociation of the 4-chlorotoluene radical anion, in corresponding arylic open-shell and chloride closed-shell species, has been studied using semiempirical ab initio methods, both cases ROHF UHF calculations have performed. It is shown that PESs are not reliable. While, at least a 3–21g basis set needed to obtain an single determinant global dissociative path (which qualitatively consistent with experimental evidence). In addition, UMP2, ROMP2, SOCI discussed, suggesting ROHF-based methods preferable UHF-based ones. This depend on spin contamination affecting wavefunction.