Incorporation of a QM/MM Buffer Zone in the Variational Double Self-Consistent Field Method

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• 作者：Wangshen Xie ; Lingchun Song ; Donald G. Truhlar ; Jiali Gao
• 刊名：Journal of Physical Chemistry B
• 出版年：2008
• 出版时间：November 13, 2008
• 年：2008
• 卷：112
• 期：45
• 页码：14124-14131
• 全文大小：226K
• 年卷期：v.112,no.45(November 13, 2008)
• ISSN：1520-5207

文摘

The explicit polarization (X-Pol) potential is an electronic-structure-based polarization force field, designed for molecular dynamics simulations and modeling of biopolymers. In this approach, molecular polarization and charge transfer effects are explicitly treated by a combined quantum mechanical and molecular mechanical (QM/MM) scheme, and the wave function of the entire system is variationally optimized by a double self-consistent field (DSCF) method. In the present article, we introduce a QM buffer zone for a smooth transition from a QM region to an MM region. Instead of using the Mulliken charge approximation for all QM/MM interactions, the Coulombic interactions between the adjacent fragments are determined directly by electronic structure theory. The present method is designed to accelerate the speed of convergence of the total energy and charge density of the system.