Explicitly correlated second-order Møller–Plesset methods with auxiliary basis sets
Explicitly correlated second-order Møller–Plesset methods with auxiliary basis sets
复制标题
与辅助基组显式相关的二阶 Møller-Plesset 方法
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
C. Samson
中科院分区：
文献类型：
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作者：
W. Klopper;C. Samson
在显式相关的Moller-Plesset （MP2-R12）方法中，一阶波函数不仅根据单电子函数（即轨道）的乘积展开，而且根据线性依赖于电子间坐标rij的双电子函数展开。使用这些函数时，会出现三电子和四电子积分，但可以通过根据单电子基插入恒等函数（RI）的分辨率来避免这些积分。在以前的工作中，电子波函数和RI近似只使用一个基。在目前的工作中，开发了一种新的计算方法，使用辅助基集来表示RI。这种辅助基使得在显式相关MP2-R12计算中使用标准基集成为可能。
In explicitly correlated Moller–Plesset (MP2-R12) methods, the first-order wave function is expanded not only in terms of products of one-electron functions—that is, orbitals—but also in terms of two-electron functions that depend linearly on the interelectronic coordinates rij. With these functions, three- and four-electron integrals occur, but these integrals can be avoided by inserting a resolution of the identity (RI) in terms of the one-electron basis. In previous work, only one single basis was used for both the electronic wave function and the RI approximation. In the present work, a new computational approach is developed that uses an auxiliary basis set to represent the RI. This auxiliary basis makes it possible to employ standard basis sets in explicitly correlated MP2-R12 calculations.