Generalized X-Pol Theory and Charge Delocalization States
Generalized X-Pol Theory and Charge Delocalization States
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DOI：
10.1021/ct100292g
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发表时间：
2010-08-01
影响因子：
5.5
通讯作者：
Mo, Yirong
中科院分区：
文献类型：
--
作者：
Gao, Jiali;Cembran, Alessandro;Mo, Yirong
在价键理论的框架下，用混合分子轨道和价键（MOVB）方法推广了显式极化势（X-Pol），引入了电荷离域共振效应。在原来的X-Pol方法中，一个大分子体系被划分成单个的片段或块，体系的分子轨道严格地定域在每个块内。在广义X-Pol（GX-Pol）理论中，我们通过将定域空间从单体嵌段扩展到成对离域嵌段来构造电荷离域VB态。因此，基空间的扩展导致单体对之间的电荷离域，并且可以构造一系列成对的离域态。通常，可以通过将L个单体嵌段分组为一个来类似地定义L体离域态。每个状态的Hartree乘积波函数可以完全反对称化，GX-Pol波函数是所有L体电荷转移的线性组合（价键）状态，其结合电荷离域和它们的共振以及静态相关效应。GX-Pol方法提供了一个通用的和严格的理论，将电荷离域明确纳入这些基于片段的大分子系统的电子结构方法中
The mixed molecular orbital and valence bond (MOVB) method has been used to generalize the explicit polarization (X-Pol) potential to incorporate charge delocalization resonance effects in the framework of valence bond theory In the original X-Pol method, a macromolecular system is partitioned into individual fragments or blocks, and the molecular orbitals of the system are strictly localized within each block Consequently, these block-localized molecular orbitals (BLMOs) are nonorthogonal across different blocks In the generalized X-Pol (GX-Pol) theory, we construct charge delocalization VB states by expanding the localization space from monomer blocks into pairwise delocalized blocks Thus, the expansion of the basis space leads to charge delocalization between monomer pairs, and a series of pairwise delocalization states can be constructed In general, L-body delocalized states can be analogously defined by grouping L monomer blocks into one The Hartree product wave function for each state can be fully antisymmetrized, which introduces explicitly exchange repulsion among all blocks The GX-Pol wave function is a linear combination of all L-body charge transfer (valence bond) states, which incorporates charge delocalization and their resonance as well as static correlation effects. The GX-Pol method provides a general and rigorous theory to incorporate charge delocalization explicitly into these fragment-based electronic structural methods for macromolecular systems