Potential energy surface discontinuities in local correlation methods.
Potential energy surface discontinuities in local correlation methods.
复制标题
局部相关方法中的势能面不连续性。
DOI：
10.1063/1.1759322
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
T. Crawford
中科院分区：
文献类型：
--
作者：
N. J. Russ;T. Crawford
我们已经研究了键断裂势能面的局部相关方法的基础上的Pulay-Saeblane轨道域方法的不连续性的发生。我们的分析集中在三个典型的离解体系：氟代甲烷的C-F键，单线态，乙烯酮的C-C键，以及丙二烯酮的中心C-C键。我们发现，这样的不连续性不会发生在均裂键裂解的情况下，由于无法的Pipek-Mezey轨道定位方法分离单线态耦合电荷遥远的片段。然而，对于异裂键裂解，如在单线态乙烯酮和丙二烯酮中观察到的，在拉伸几何形状和接近平衡时都发生不连续性。这些不连续性通常很小，但在某些情况下可能与定位误差具有相同的数量级。
We have examined the occurrence of discontinuities in bond-breaking potential energy surfaces given by local correlation methods based on the Pulay-Saebø orbital domain approach. Our analysis focuses on three prototypical dissociating systems: the C-F bond in fluoromethane, the C-C bond in singlet, ketene, and the central C-C bond in propadienone. We find that such discontinuities do not occur in cases of homolytic bond cleavage due to the inability of the Pipek-Mezey orbital localization method to separate singlet-coupled charges on distant fragments. However, for heterolytic bond cleavage, such as that observed in singlet ketene and propadienone, discontinuities occur both at stretched geometries and near equilibrium. These discontinuities are usually small, but may be of the same order of magnitude as the localization error in some cases.