A program system for ab initio MO calculations on vector and parallel processing machines III. Integral reordering and four-index transformation

Abstract This series of three papers presents a program system for ab initio molecular orbital calculations on vector and parallel computers. Part III is devoted to the four-index transformation on a molecular orbital basis of size NMO of the file of two-electron integrals (pq∥rs) generated by a contracted Gaussian set of size NATO (number of atomic orbitals). A fast Yoshimine algorithm first sorts the (pq∥rs) integrals with respect to index pq only. This file of half-sorted integrals labelled by thei... Title of program: ASTERIX-REORD, ASTERIX-TRANSF Catalogue Id: ABTA_v1_0 Nature of problem The evaluation of the correlation energy through Complete Active Space SCF iterations or CI expansion requires a file of two-electron integrals expressed over the basis of molecular orbitals (MOs) involved in the post-SCF treatment. Assuming that these MOs are known linear combinations of the initial atomic basis set, the present programs compute the integrals over the MO basis starting from a file of randomly distributed two-electron integrals expressed over the atomic orbital basis. Versions of this program held in the CPC repository in Mendeley Data ABTA_v1_0; ASTERIX-REORD, ASTERIX-TRANSF; 10.1016/0010-4655(91)90125-5 This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2018)摘要 本系列三篇论文针对向量与并行计算机上的从头算分子轨道（ab initio molecular orbital）计算，提出一套程序系统。第三部分聚焦于由规模为NATO（原子轨道数）的收缩高斯基组生成的(pq∥rs)型双电子积分文件，针对大小为NMO的分子轨道基组完成四指标变换（four-index transformation）。首先采用高效的Yoshimine算法（Yoshimine algorithm）仅按指标pq对(pq∥rs)型双电子积分进行排序，得到以半排序积分组成的、由……标记的文件…… 程序名称：ASTERIX-REORD、ASTERIX-TRANSF 目录编号：ABTA_v1_0 问题本质 通过完全活性空间自洽场（Complete Active Space SCF, CASSCF）迭代或组态相互作用（CI, Configuration Interaction）展开计算相关能时，需要一套基于后SCF处理所用分子轨道（MO）基组的双电子积分文件。假设上述分子轨道为初始原子基组的已知线性组合，本程序可从基于原子轨道基组的随机分布双电子积分文件出发，计算得到分子轨道基组下的双电子积分。 本程序收录于Mendeley数据平台的《计算机物理学报》（Computer Physics Communications, CPC）程序库版本： ABTA_v1_0; ASTERIX-REORD, ASTERIX-TRANSF; 10.1016/0010-4655(91)90125-5 本程序源自贝尔法斯特女王大学维护的CPC程序库（1969-2018）