Analytical energy gradient for the reference interaction site model multiconfigurational self‐consistent‐field method: Application to 1,2‐difluoroethylene in aqueous solution
Analytical energy gradient for the reference interaction site model multiconfigurational self‐consistent‐field method: Application to 1,2‐difluoroethylene in aqueous solution
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参考相互作用位点模型多构型自洽场方法的分析能量梯度：在水溶液中的 1,2-二氟乙烯的应用
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
S. Kato
中科院分区：
文献类型：
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作者：
Hirofumi Sato;F. Hirata;S. Kato
我们重新制定了参考相互作用位点模型自洽场（RISM‐SCF）方法来计算溶液中溶质的分子性质。其主要特点是引入亥姆霍兹自由能，作为从头计算分子轨道（MO）方法估计的溶质电子能和超网链（HNC）溶剂化的过量化学势的总和，用于扩展的参考相互作用位点模型（XRISM）方法。导出了多组态自洽场（MCSCF）波函数的变分条件。它还表明，在Hartree-Fock（HF）方法的情况下，本表达式给出了相同的Fock矩阵先前定义的。此外，还得到了自由能对溶质核坐标的一阶导数表达式。给出了1，2-二氟乙烯顺式和反式异构体化学平衡的计算示例。利用MCSCF和HF方法的分析能量梯度，
We have reformulated the reference interaction site model self‐consistent‐field (RISM‐SCF) method to calculate the molecular properties of solute in solutions. The key feature is to introduce the Helmholtz free energy given as a sum of the solute electronic energy estimated by ab initio molecular orbital (MO) methods and the hypernetted‐chain (HNC) excess chemical potential of solvation for the extended reference interaction site model (XRISM) method. The variational conditions for the multiconfigurational self‐consistent‐field (MCSCF) wave functions were derived. It was also shown that, in the case of the Hartree–Fock (HF) method, the present expression gives the same Fock matrix defined previously. Moreover the expression for first derivatives of the free energy with respect to the solute nuclear coordinates were obtained. Sample calculations for the chemical equilibrium of cis‐ and trans‐isomers of 1,2‐difluoroethylene are presented. With the use of analytical energy gradients for the MCSCF and HF meth...