Automated Quantum Chemistry Code Generation with the p†q Package.

Abstract

This article summarizes recent updates to the p^†q package, which is a C++ accelerated Python library for generating equations and computer code corresponding to singly referenced many-body quantum chemistry methods such as coupled-cluster (CC) and equation-of-motion (EOM) CC theory. Since 2021, the functionality in p^†q has expanded to include boson operators, coupled fermion-boson operators, unitary cluster operators, non-particle-conserving EOM operators, spin tracing, multiple single-particle subspaces, and more. Additional developments allow for the generation of C++ and Python code that minimizes floating-point operations via contraction order optimization, subexpression elimination, and the fusion of similar terms.