English

Relativistic coupled cluster with completely renormalized and perturbative triples corrections

Chemical Physics 2024-06-21 v2

Abstract

We have implemented noniterative triples corrections to the energy from coupled-cluster with single and double excitations (CCSD) within the 1-electron exact two-component (1eX2C) relativistic framework. The effectiveness of both the CCSD(T) and the completely renormalized (CR) CC(2,3) approaches are demonstrated by performing all-electron computations of the potential energy curves and spectroscopic constants of copper, silver, and gold dimers in their ground electronic states. Spin-orbit coupling effects captured via the 1eX2C framework are shown to be crucial for recovering the correct shape of the potential energy curves, and the correlation effects due to triples in these systems changes the dissociation energies by about 0.1--0.2 eV or about 4--7\%. We also demonstrate that relativistic effects and basis set size and contraction scheme are significantly more important in Au2_2 than in Ag2_2 or Cu2_2.

Keywords

Cite

@article{arxiv.2404.13231,
  title  = {Relativistic coupled cluster with completely renormalized and perturbative triples corrections},
  author = {Stephen H. Yuwono and Run R. Li and Tianyuan Zhang and Kshitijkumar A. Surjuse and Edward F. Valeev and Xiaosong Li and A. Eugene DePrince},
  journal= {arXiv preprint arXiv:2404.13231},
  year   = {2024}
}