Automated evaluation of matrix elements between contracted wavefunctions: A Mathematica version of the FRODO program

Abstract
A symbolic program performing the Formal Reduction of Density Operators (FRODO), formerly developed in the MuPAD computer algebra system with the purpose of evaluating the matrix elements of the electronic Hamiltonian between internally contracted functions in a complete active space (CAS) scheme, has been rewritten in Mathematica.

Title of program: FRODO
Catalogue Id: ADVY_v2_0

Nature of problem
In order to improve on the CAS-SCF wavefunction one can resort to multireference perturbation theory or configuration interaction based on internally contracted functions (ICF) which are obtained by application of the excitation operators to the reference CAS-SCF wavefunction. The previous formulation of such matrix elements in the MuPAD computer algebra system, has been rewritten using Mathematica.

Versions of this program held in the CPC repository in Mendeley Data
ADVY_v1_0; FRODO; 10.1016/j.cpc.2005.05.002
ADVY_v2_0; FRODO; 10.1016/j.cpc.2012.09.034

This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2018)

摘要
一个执行形式密度算符正规约简（FRODO）的符号程序，此前在MuPAD计算机代数系统中开发，旨在评估完整有效空间（CAS）方案中内部收缩函数之间的电子哈密顿矩阵元素，现已重写为Mathematica版本。

程序名称：FRODO
目录编号：ADVY_v2_0

问题性质
为了改进CAS-SCF波函数，可以求助于基于内部收缩函数（ICF）的多参考微扰理论或构型相互作用，这些函数是通过激发算符作用于参考CAS-SCF波函数获得的。此类矩阵元素在MuPAD计算机代数系统中的先前公式已使用Mathematica重写。

此程序版本存放在Mendeley数据中CPC程序库
ADVY_v1_0；FRODO；10.1016/j.cpc.2005.05.002
ADVY_v2_0；FRODO；10.1016/j.cpc.2012.09.034

该程序已从贝尔法斯特女王大学（1969-2018）的CPC程序库导入。