A study of molecular pair potentials; A semiempirical approach

摘要: An expression is developed for the short range molecular pair potentials within framework of Heitler–London approach molecules in a closed shell state. Assumptions common with CNDO/2 semiempirical method are employed evaluating integrals. The final depends only on quantities related to atoms making up each molecule. There four such quantities; (1) atom charge density Pm; (2) core Zcm; (3) distance between rmn; and (4) value two electron repulsion integrals γmn. In terms these has simple form E(1)ab= (−1) Σm(a)Σn(b) [PmPnγmn(Zcm/Pm+Zcn/Pn −1)−ZcmZcnr−1mn]. Although several approximations introduced obtain this evaluation integrals, no adjustable parameters required evluation E(1)ab. This potential good agreement results ab initio calculations system He/H2, Ne/H2, HF/HF. A c...