A general program for computing angular integrals of the Breit–Pauli Hamiltonian with non-orthogonal orbitals

Abstract
The BREIT_NO program performs the angular integrations necessary for expressing the matrix elements of the Breit–Pauli Hamiltonian as a linear combination of radial integrals. Any amount of non-orthogonality between the orbitals may be present leading to overlap factors in the matrix elements. The calculations follow the method based on the representation of configuration wave functions through the Slater determinants. All matrix elements for a given list of configuration states may be evalua...

Title of program: BREIT_NO
Catalogue Id: ADLA_v1_0

Nature of problem
In many atomic processes involving inner atomic shells, the relaxation of electron orbitals plays an important role. The relaxation can be most naturally taken into consideration by using non-orthogonal orbitals for the initial and final state. In atomic structure calculations, the rate of convergence of the many-configuration expansion to an acceptable accuracy may be much faster if the orbitals associated with different configurations and terms are not necessarily required to be orthogonal. Th ...

Versions of this program held in the CPC repository in Mendeley Data
ADLA_v1_0; BREIT_NO; 10.1016/S0010-4655(99)00441-5

This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2019)

摘要
BREIT_NO程序可完成将布雷特-泡利哈密顿量（Breit–Pauli Hamiltonian）的矩阵元表示为径向积分线性组合所需的角积分运算。轨道间可存在任意程度的非正交性，此类非正交性会在矩阵元中引入重叠因子。本计算采用基于斯莱特行列式（Slater determinant）表征组态波函数的方法。针对给定的组态态列表，可计算全部矩阵元……

程序名称：BREIT_NO
目录号：ADLA_v1_0

问题本质
在诸多涉及原子内壳层的原子过程中，电子轨道的弛豫效应具有重要作用。若为初态与末态采用非正交轨道，则可最自然地纳入弛豫效应的考量。在原子结构计算中，若无需强制要求对应不同组态与谱项的轨道保持正交，则多组态展开收敛至可接受精度的速率可大幅提升……

存放在Mendeley Data的CPC知识库中的该程序版本：
ADLA_v1_0；BREIT_NO；10.1016/S0010-4655(99)00441-5

本程序源自贝尔法斯特女王大学维护的CPC程序库（1969-2019）