Cembran Alessandro, Bao Peng, Wang Yingjie, Song Lingchun, Truhlar Donald G, Gao Jiali
Department of Chemistry and Minnesota Supercomputing Institute University of Minnesota, Minneapolis, MN 55455.
J Chem Theory Comput. 2010;6(8):2469-2476. doi: 10.1021/ct100268p.
The inclusion of exchange repulsion terms in the explicit polarization (X-Pol) model is examined by antisymmetrizing the X-Pol Hartree-product wave function; this yields XPol with full eXchange, called X-Pol-X. When the monomers are treated by Hartree-Fock theory, this calculation can be accomplished by using the formalism of block-localized wave functions (BLW) that has been used in a variety of applications. In this case the block-localized structure in the X-Pol-X wave function allows for decomposition of the full Fock matrix of a dimension of M blocks into M smaller Fock matrices. The method is illustrated by considering two trimer structures of water clusters, and it is found that the total exchange repulsion energies in these hydrogen-bonding test cases are adequately treated and-to a good approximation- are pairwise additive. We also present a formalism to yield a simplified Fock matrix by making use of the neglect of interfragment differential overlap (NIDO) approximation, which is less severe than the neglect of diatomic differential overlap (NDDO) approximation.
通过对X-Pol哈特里积波函数进行反对称化来研究显式极化(X-Pol)模型中交换排斥项的包含情况;这产生了具有完全交换的XPol,称为X-Pol-X。当单体用哈特里-福克理论处理时,这种计算可以通过使用已在各种应用中使用的块定域波函数(BLW)形式来完成。在这种情况下,X-Pol-X波函数中的块定域结构允许将维度为M个块的完整福克矩阵分解为M个较小的福克矩阵。通过考虑水团簇的两种三聚体结构来说明该方法,并且发现在这些氢键测试案例中的总交换排斥能得到了充分处理,并且在良好近似下是成对加和的。我们还提出了一种形式主义,通过利用片段间微分重叠忽略(NIDO)近似来产生简化的福克矩阵,该近似比双原子微分重叠忽略(NDDO)近似的程度要轻。