The externally corrected coupled cluster approach with four- and five-body clusters from the CASSCF wave function

The Journal of Chemical Physics
Enhua Xu, Shuhua Li

Abstract

An externally corrected CCSDt (coupled cluster with singles, doubles, and active triples) approach employing four- and five-body clusters from the complete active space self-consistent field (CASSCF) wave function (denoted as ecCCSDt-CASSCF) is presented. The quadruple and quintuple excitation amplitudes within the active space are extracted from the CASSCF wave function and then fed into the CCSDt-like equations, which can be solved in an iterative way as the standard CCSDt equations. With a size-extensive CASSCF reference function, the ecCCSDt-CASSCF method is size-extensive. When the CASSCF wave function is readily available, the computational cost of the ecCCSDt-CASSCF method scales as the popular CCSD method (if the number of active orbitals is small compared to the total number of orbitals). The ecCCSDt-CASSCF approach has been applied to investigate the potential energy surface for the simultaneous dissociation of two O-H bonds in H2O, the equilibrium distances and spectroscopic constants of 4 diatomic molecules (F2(+), O2(+), Be2, and NiC), and the reaction barriers for the automerization reaction of cyclobutadiene and the Cl + O3 → ClO + O2 reaction. In most cases, the ecCCSDt-CASSCF approach can provide better results...Continue Reading

References

Nov 9, 1992·Physical Review Letters·S R White
Jul 23, 2004·The Journal of Chemical Physics·Garnet Kin-Lic Chan
Dec 21, 2004·The Journal of Chemical Physics·So HirataPiotr Piecuch
Mar 4, 2005·The Journal of Chemical Physics·Karol Kowalski, Piotr Piecuch
Oct 19, 2005·The Journal of Chemical Physics·Tomoko KinoshitaRodney J Bartlett
Dec 27, 2005·The Journal of Chemical Physics·Piotr Piecuch, Marta Włoch
May 13, 2006·The Journal of Chemical Physics·Xiangzhu Li, Josef Paldus
Jul 21, 2007·The Journal of Chemical Physics·Francesco A EvangelistaHenry F Schaefer
Nov 13, 2007·The Journal of Chemical Physics·Yingbin GePiotr Piecuch
Feb 6, 2008·The Journal of Chemical Physics·Andrew G Taube, Rodney J Bartlett
Apr 17, 2008·The Journal of Chemical Physics·Debashree GhoshGarnet Kin-Lic Chan
Jul 4, 2008·Physical Chemistry Chemical Physics : PCCP·Jeremy M MerrittMichael C Heaven
Aug 14, 2008·The Journal of Chemical Physics·Xiangzhu Li, Josef Paldus
Dec 3, 2008·The Journal of Chemical Physics·Xiangzhu Li, Josef Paldus
Mar 26, 2011·Physical Chemistry Chemical Physics : PCCP·J F CastilloB Martínez-Haya
Jan 10, 2012·Chemical Reviews·Dmitry I LyakhRodney J Bartlett
Apr 3, 2012·The Journal of Chemical Physics·Sandeep Sharma, Garnet Kin-Lic Chan
Jun 7, 2012·The Journal of Chemical Physics·Matthias Hanauer, Andreas Köhn

❮ Previous
Next ❯

Citations

Jan 15, 2016·Journal of Chemical Theory and Computation·Wenjian Liu, Mark R Hoffmann
Feb 14, 2019·Physical Chemistry Chemical Physics : PCCP·César X Almora-DíazCarlos F Bunge
Jun 24, 2021·Journal of Chemical Theory and Computation·Ilias MagoulasJun Shen
Dec 5, 2020·Journal of Chemical Theory and Computation·Gustavo J R AroeiraHenry F Schaefer

❮ Previous
Next ❯

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.