Combining Effective Hamiltonians and Brillouin-Wigner Approach: A Perturbative Approach to Spectroscopy
Chemical Physics
2024-08-30 v1
Abstract
The numerical cost of variational methods suggests using perturbative approaches to determine the electronic structure of molecular systems. In this work, a sequential construction of effective Hamiltonians drives the definition of approximate model functions and energies in a multi-state Rayleigh-Schr\"odinger perturbative scheme. A second step takes advantage of an updated partitioning of the Hamiltonian to perform a state-specific Brillouin-Wigner energy correction based on a well-tempered perturbation expansion. The multi-step RSBW method is exemplified on model-Hamiltonians to stress its robustness, efficiency and applicability to spectroscopy determination.
Keywords
Cite
@article{arxiv.2408.16505,
title = {Combining Effective Hamiltonians and Brillouin-Wigner Approach: A Perturbative Approach to Spectroscopy},
author = {Oussama Bindech and Bastien Valentin and Saad Yalouz and Vincent Robert},
journal= {arXiv preprint arXiv:2408.16505},
year = {2024}
}