SpinAdaptedSecondQuantization.jl 1.0 -- A Simple and Pedagogical Approach to Symbolic Quantum Chemistry

TL;DR

SpinAdaptedSecondQuantization.jl is an open-source Julia package that simplifies the development and prototyping of electronic structure methods, supporting spin-adapted operators and automated derivation of quantum chemistry equations.

Contribution

It introduces a user-friendly, extensible software tool for automated electronic structure theory development with spin adaptation and symbolic expression translation capabilities.

Findings

Facilitates rapid prototyping of new electronic structure methods.

Supports exotic systems with mixed particle types.

Automates derivation of key quantum chemistry equations.

Abstract

The development of new electronic structure methods is a very time consuming and error prone process when done by hand. SpinAdaptedSecondQuantization is an open-source Julia package we have developed for working with automated electronic structure theory development. The code focuses on being user-friendly and extensible, allowing for easy use of both user- and pre-defined fermionic and/or bosonic operators, tensors, and orbital spaces. This allows the code to be used to efficiently investigate and prototype new electronic structure methods for many different types of systems. This includes both exotic systems with wave functions consisting of different kinds of particles at once, as well as new parametrizations for traditional many-electron systems. The code is spin-adapted, working directly with spin-adapted fermionic operators, and can easily be used to derive common electronic structure theory equations and expressions, such as the coupled cluster energy, ground and excited state equations, one- and two-electron density matrices, etc. Additionally, the code can translate expressions into code, accelerating the process of going from ideas to implemented methods.