Automatic code generation enables nuclear gradient computations for fully internally contracted multireference theory
Chemical Physics
2015-02-11 v2
Abstract
Analytical nuclear gradients for fully internally contracted complete active space second-order perturbation theory (CASPT2) are reported. This implementation has been realized by an automated code generator that can handle spin-free formulas for the CASPT2 energy and its derivatives with respect to variations of molecular orbitals and reference coefficients. The underlying complete active space self-consistent field and the so-called Z-vector equations are solved using density fitting. The implementation has been applied to the vertical and adiabatic ionization potentials of the porphin molecule to illustrate its capability.
Keywords
Cite
@article{arxiv.1501.02780,
title = {Automatic code generation enables nuclear gradient computations for fully internally contracted multireference theory},
author = {Matthew K. MacLeod and Toru Shiozaki},
journal= {arXiv preprint arXiv:1501.02780},
year = {2015}
}