The second-order approximate internally contracted multireference coupled-cluster singles and doubles method icMRCC2

The Journal of Chemical Physics
Andreas Köhn, Arne Bargholz

Abstract

The second-order approximate internally contracted multireference coupled-cluster singles and doubles method icMRCC2 is defined and tested. The method is designed to bridge the gap between multireference perturbation theory and single-reference second-order approximate coupled-cluster theory (CC2). By including semi-internal double excitations into the zeroth-order expansion, the new method is able to reliably describe the coupling between excitations within the active space and the entire single-excitation spectrum. This helps, for instance, to provide a balanced treatment of valence and ionic states in polyenes (as explicitly demonstrated for cyclopentadiene) and to arrive at a more complete coverage of the excitation spectrum without the need to include diffuse orbitals into the active space. Good performance is also seen for notoriously difficult molecules such as C2 and CN. Furthermore, the multireference extension removes the main failures of single-reference CC2 theory, such as in the case of ozone.

References

Sep 15, 1987·Physical Review. B, Condensed Matter·P Tavan, K Schulten
Apr 10, 2008·The Journal of Chemical Physics·Marko SchreiberWalter Thiel
Mar 25, 2011·The Journal of Chemical Physics·Francesco A Evangelista, Jürgen Gauss
Jun 7, 2012·The Journal of Chemical Physics·Matthias Hanauer, Andreas Köhn
Oct 9, 2012·The Journal of Chemical Physics·Matthias Hanauer, Andreas Köhn
Dec 5, 2012·The Journal of Chemical Physics·Dipayan Datta, Marcel Nooijen
Apr 10, 2014·The Journal of Chemical Physics·Pradipta Kumar SamantaAndreas Köhn
Aug 13, 2013·Journal of Chemical Theory and Computation·Igor SchapiroFrank Neese
Sep 9, 2014·Journal of Chemical Theory and Computation·Dániel Kánnár, Péter G Szalay
Jun 3, 2017·Chemical Science·J Patrick ZobelLeticia González
Jan 29, 2019·Journal of Chemical Theory and Computation·Pierre-François LoosDenis Jacquemin
Feb 23, 2019·Journal of Chemical Theory and Computation·Yuri Alexandre AotoAndreas Köhn
May 24, 2019·The Journal of Chemical Physics·Joshua A Black, Andreas Köhn

❮ Previous
Next ❯

Citations

Apr 17, 2020·The Journal of Chemical Physics·Hans-Joachim WernerMarat Sibaev
Aug 7, 2021·Physical Chemistry Chemical Physics : PCCP·Abhishek Khedkar, Michael Roemelt
Sep 3, 2020·Journal of Chemical Theory and Computation·Koushik Chatterjee, Alexander Yu Sokolov
Sep 24, 2021·Journal of Chemical Theory and Computation·Ilia M Mazin, Alexander Yu Sokolov

❮ 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.