Development of a new molecular orbital theory for avoiding the basis set superposition error in the molecular interaction energy

发展新的分子轨道理论以避免分子相互作用能中的基组叠加误差

基本信息

批准号：
14540479
负责人：
IWATA Suehiro
金额：
$ 1.79万
依托单位：
HIROSHIMA UNIVERSITY (2004)National Institution for Academic Degrees and University Evaluation (2002-2003)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

项目摘要

1)For the clusters consisting of the closed shell molecules, the MP2 level of theory based on the locally-projected molecular orbital theory (LP MO) was developed, and the computer codes were written. A few test calculations showed promising results ; a)the calculated binding energy with the charge-transfer terms is close to the counterpoise corrected SCF binding energy. b)The dispersion-exchange term contributes substantially to the binding energy, particularly near the potential energy minimum.2)The basis set superpose error(BSSE) for the one-electron properties are examined, and are compared with the LP MO MP2(CT). It turns out that the BSSE is less serious than for the binding energy in most of the examples examined.3)Using the projection operators, the stationary condition for closed shell and high-spin open shell molecular orbital coefficients is derived without the orthogonality condition, and a method to solve the equation is proposed. It can be an alternative and direct method to obtain the localized molecular orbitals4)The equations of LP MO for the high-spin open shell cluster, which consists of one open shell molecule and many closed shell molecules, is derived, and the coding is under development.5)With LP MO method and MP2 method, the ionic clusters, M^+(Ar)_n (M=Li,Na,K) were studied. By examining the optimized geometries and the potential energy surfaces, the interaction terms are analyzed.

1)针对闭壳层分子组成的团簇,提出了基于局域投影分子轨道理论(LP MO)的MP2层次理论,并编写了计算机代码。一些测试计算显示出有希望的结果； a) 用电荷转移项计算的结合能接近于平衡校正的 SCF 结合能。 b) 色散交换项对结合能有很大贡献，特别是在势能最小值附近。2) 检查单电子性质的基组叠加误差 (BSSE)，并与 LP MO MP2(CT) 进行比较）。事实证明，在大多数研究的例子中，BSSE 没有结合能那么严重。3) 使用投影算子，在没有正交条件的情况下导出了闭壳层和高自旋开壳层分子轨道系数的平稳条件，并提出了求解该方程的方法。 4)推导了由一个开壳层分子和多个闭壳层分子组成的高自旋开壳层团簇的LP MO方程，并给出了编码5)采用LP MO法和MP2法对离子团簇M^+(Ar)_n (M=Li,Na,K)进行了研究。通过检查优化的几何形状和势能面，分析相互作用项。