Hilbert space multireference coupled cluster tailored by matrix product states.

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388955%3A_____%2F23%3A00580139" target="_blank" >RIV/61388955:_____/23:00580139 - isvavai.cz</a>

Alternative codes found

RIV/00216208:11310/23:10480047

Result on the web

<a href="https://hdl.handle.net/11104/0348905" target="_blank" >https://hdl.handle.net/11104/0348905</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1063/5.0174461" target="_blank" >10.1063/5.0174461</a>

Result language

angličtina

Original language name

Hilbert space multireference coupled cluster tailored by matrix product states.

Original language description

In the past decade, the quantum chemical version of the density matrix renormalization group method has established itself as the method of choice for strongly correlated molecular systems. However, despite its favorable scaling, in practice, it is not suitable for computations of dynamic correlation. Several approaches to include that in post-DMRG methods exist, in our group, we focused on the tailored coupled cluster (TCC) approach. This method works well in many situations. However, in exactly degenerate cases (with two or more determinants of equal weight), it exhibits a bias toward the reference determinant representing the Fermi vacuum. Although sometimes it is possible to use a compensation scheme to avoid this bias for energy differences, it is certainly a drawback. In order to overcome this bias of the TCC method, we have developed a Hilbert-space multireference version of tailored CC, which can treat several determinants on an equal footing. We have implemented and compared the performance of three Hilbert-space multireference coupled cluster (MRCC) variants-the state universal one and the Brillouin-Wigner and Mukherjee's state specific ones. We have assessed these approaches on the cyclobutadiene and tetramethyleneethane molecules, which are both diradicals with exactly degenerate determinants at a certain geometry. We have also investigated the sensitivity of the results on the orbital rotation of the highest occupied and lowest unoccupied molecular orbital (HOMO-LUMO) pair, as it is well known that Hilbert-space MRCC methods are not invariant to such transformations.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10403 - Physical chemistry

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2023

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of Chemical Physics

ISSN

0021-9606

e-ISSN

1089-7690

Volume of the periodical

159

Issue of the periodical within the volume

22

Country of publishing house

US - UNITED STATES

Number of pages

14

Pages from-to

224115

UT code for WoS article

001126141400006

EID of the result in the Scopus database

2-s2.0-85179772948