物理化学学报 >> 1986, Vol. 2 >> Issue (06): 512-518.doi: 10.3866/PKU.WHXB19860606

研究论文 上一篇    下一篇

CNDO/2法的碎片价轨道近似 Ⅰ. 原理

曹怀贞; 刘春万; 卢嘉锡   

  1. 中国科学院福建物质结构研究所, 福州
  • 收稿日期:1985-07-09 修回日期:1986-01-25 发布日期:1986-12-15

FRAGMENT VALENCE ORBITAL APPROXIMATION OF THE CNDO-FORMALISM I. PRINCIPLE

Cao Huaizhen; Liu Chunwan; Lu Jiaxi   

  1. Fujian Institute of Research on the Structure of Matter; Academia Sinica; Fuzhou
  • Received:1985-07-09 Revised:1986-01-25 Published:1986-12-15

摘要: 本文提出一种简化的处理方法, 在研究桥联原子簇化合物电子结构时把端基看成碎片, 取碎片的部分价轨道参与整个分子的计算以节约机时, 在CND0/2法基础上推导出碎片价轨道近似法的公式, 并用FORTRAN语言编写程序, 在PDP-11-70机上实现。本法可望用于较大分子体系的局部几何构型优化及反应机理等计算量较大的研究。

Abstract: A simplified MO treatment has been proposed for the cluster compounds containing both bridging and terminal ligands. The terminal ligands of a considered cluster can be treated as fragment, if only the electronic structures of the skeleton are interested in We chose a pars of the fragment MO's in the terminal ligands which are calculated beforhand as the valence orbitals of these fragments and retain a common set of skeleton atoms which is treated as in standard CNDO. The largest advantage of this approximation is in the reduction of the number of electrons and basis functions, and hance the reduction of computer time. The detailed description of the formalism has been presented and the procedure of the calculation has been programed and performed on a PDP-11-70 computer.