HX体系电子对内、对间相关研究

在6-311+G^*基组水平上用CISD（configurationinteractionwithsinglyanddoublyexcitedconfigurations)方法研究HX(X=Li-F,HBe)体系电子对内、对间的相关能。计算结果表明不同元素形成的HX(X=Li-F,HBe^+,HBe)体系，其价层电子对内、对间相关能的变化较大，它们之间存在着轨道差别，不宜将其相关贡献归为简单的常数。在使用相同理论方法和相同质量基组的前提下，电子数将直接影响到电子对间相关能的大小。对于多电子体系，电子对间相关在总相关中占有优势，若将其忽略会引起较大误差。

Studies on the intrapair and interpair correlation of electrons of HX

The intrapair and interpair correlation energies of electrons of HX(X = Li - F, HBe , HBe) have been studied by CISD(configuration interaction with singly and doubly excited configurations)method with 6 -311 G* basis set. It has been found that the electron intrapair and interpair correlation energies are very sensible to orbitals (except the inner orbitals) . Furthermore, the changes of intrapair and interpair energies of valence electrons are very great in the different element - formed systems. Under the conditions of the same theoretical method and the same basis sets, the number of electrons will affect directly the values of interpair correlation energies of electrons. If a system has many electrons, the total electron interpair correlation energy will dominate in the total electron correlation energy. This reminds us that we should take the importance of interpair of electrons and the difference of orbitals into consideration while further correcting the caculated result of Post - HF.