Development of Xi'an-CI package - applying the hole-particle symmetry in multi-reference electronic correlation calculations
Development of Xi'an-CI package - applying the hole-particle symmetry in multi-reference electronic correlation calculations
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Xi'an-CI包的开发——空穴-粒子对称性在多参考电子相关计算中的应用
DOI：
10.1080/00268976.2018.1441464
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发表时间：
2018
影响因子：
1.7
通讯作者：
Wang Yubin
中科院分区：
文献类型：
--
作者：
Suo Bingbing;Lei Yibo;Han Huixian;Wang Yubin
本文简要介绍了我们在西安组态相互作用软件包上使用图酉群方法（GUGA）所做的工作。利用GUGA中的空穴-粒子对称性，将用于跨越CI空间的Galfand态按空穴和粒子的数目划分为CI子空间，并将用于计算哈密顿矩阵元的耦合系数分解为空穴、活性和外部空间的分段因子.因此，开发了一种高效的单双激发多参考CI（MRCISD）算法，该算法降低了存储需求并显着增加了相关电子的数量。空穴-粒子对称性也产生了双重收缩的MRCISD方法。此外，内收缩Gelfand态被定义在由空穴-粒子对称性产生的CI子空间内，这使得在GUGA框架下实现内收缩MRCISD成为可能。除了MRCISD，多参考二阶微扰理论（MRPT 2）的发展也得益于空穴-粒子对称性。提出了一种基于组态的MRPT 2算法，并将其推广到多态电子价态二级微扰理论。
This mini-review introduces our works on the Xi'an-CI (configuration interaction) package using graphical unitary group approach (GUGA). Taking advantage of the hole-particle symmetry in GUGA, the Galfand states used to span the CI space are classified into CI subspaces according to the number of holes and particles, and the coupling coefficients used to calculate Hamiltonian matrix elements could be factorised into the segment factors in the hole, active and external spaces. An efficient multi-reference CI with single and double excitations (MRCISD) algorithm is thus developed that reduces the storage requirement and increases the number of correlated electrons significantly. The hole–particle symmetry also gives rise to a doubly contracted MRCISD approach. Moreover, the internally contracted Gelfand states are defined within the CI subspace arising from the hole–particle symmetry, which makes the implementation of internally contracted MRCISD in the framework of GUGA possible. In addition to MRCISD, the development of multi-reference second-order perturbation theory (MRPT2) also benefits from the hole–particle symmetry. A configuration-based MRPT2 algorithm is proposed and extended to the multi-staten-electron valence-state second-order perturbation theory.