A novel method which makes full use of point groups including Abeian and nonAbelian groups is presented. The key point for this method is the definition of a kind of newsymmetry moecular orbitals (SMOs). Any group ele...A novel method which makes full use of point groups including Abeian and nonAbelian groups is presented. The key point for this method is the definition of a kind of newsymmetry moecular orbitals (SMOs). Any group element in a moecular point group willtransform one SMO to another equlvalent SMO and no mixture among SMCh exists. The unique feature will be kept for one or two - electron integrals as well as the Slater determinantsconstructed using SMCh. Consequently, the character integrals and character detendnants(CDs) can be selected according to some simple rules. Based on this method, a preliminarycharacter single and doubly excited single reference CI (CD - SR - CISD) program is developed, and pilot calculations are performed and compared with GAUSSIAN - 94.For thehigh symmetry point group models and linear molecules our CD - CISD program costs lessCPU - time than G94 - CISD and the storage demand of CD - CISD is also remarkably alleviated.展开更多
文摘A novel method which makes full use of point groups including Abeian and nonAbelian groups is presented. The key point for this method is the definition of a kind of newsymmetry moecular orbitals (SMOs). Any group element in a moecular point group willtransform one SMO to another equlvalent SMO and no mixture among SMCh exists. The unique feature will be kept for one or two - electron integrals as well as the Slater determinantsconstructed using SMCh. Consequently, the character integrals and character detendnants(CDs) can be selected according to some simple rules. Based on this method, a preliminarycharacter single and doubly excited single reference CI (CD - SR - CISD) program is developed, and pilot calculations are performed and compared with GAUSSIAN - 94.For thehigh symmetry point group models and linear molecules our CD - CISD program costs lessCPU - time than G94 - CISD and the storage demand of CD - CISD is also remarkably alleviated.
