Double Ionization Potential Equation-of-Motion Coupled-Cluster Approach with Full Inclusion of 4-Hole-2-Particle Excitations and Three-Body Clusters

Autor:	Gururangan, Karthik, Dutta, Achintya Kumar, Piecuch, Piotr
Rok vydání:	2024
Předmět:	Physics - Chemical Physics Physics - Computational Physics
Druh dokumentu:	Working Paper
Popis:	The double ionization potential (DIP) equation-of-motion (EOM) coupled-cluster (CC) method with a full treatment of 4-hole-2-particle (4$h$-2$p$) correlations and triply excited clusters, abbreviated as DIP-EOMCCSDT(4$h$-2$p$), and its approximate form called DIP-EOMCCSD(T)(a)(4$h$-2$p$) have been formulated and implemented in the open-source CCpy package available on GitHub. The resulting codes work with both nonrelativistic and spin-free scalar-relativistic Hamiltonians. By examining the DIPs of Cl$_{2}$, Br$_{2}$, and HBr, for which accurate experimental data are available, we demonstrate that the DIP-EOMCCSDT(4$h$-2$p$) and DIP-EOMCCSD(T)(a)(4$h$-2$p$) approaches improve the results obtained using the DIP-EOMCC methods truncated at 3$h$-1$p$ or 4$h$-2$p$ excitations on top of the CC calculations with singles and doubles. Comment: 7 pages and 3 tables. This article has been submitted to the Journal of Chemical Physics
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/2412.10688 Zobrazit plný text záznamu View this record from Arxiv