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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Reference spaces for multireference coupled-cluster theory: the challenge of the CoH molecule

Full text
Author(s):
de Moraes, Matheus Morato F. [1] ; Aoto, Yuri Alexandre [1]
Total Authors: 2
Affiliation:
[1] Fed Univ ABC UFABC, Ctr Math Comp & Cognit, Ave Estados 5001, Santo Andre, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: THEORETICAL CHEMISTRY ACCOUNTS; v. 139, n. 4 MAR 27 2020.
Web of Science Citations: 0
Abstract

In multireference calculations on transition metal compounds, large active spaces including a second set of d orbitals are often used. However, with the increase in the system size and the complexity of the method, such calculations quickly become impractical. In this work, we looked for an inner valence active space for atomic cobalt and its hydride that correctly describes the transition energies among states with distinct configurations. Potential energy curves for the CoH molecule were obtained using a fixed reference space, where the orbitals are optimised only for the isolated atoms, avoiding undesirable sudden variations of the active orbitals. The calculations made use of the multireference configuration interaction (MRCI) and coupled-cluster (MRCC) theories. The accuracy of these calculations is carefully analysed, and we show that MRCC results are accurate, although not all electronic states are quantitatively described at the MRCI level. We conclude that the use of the fixed reference space is a viable approach to reduce the computational cost when large active spaces are prohibitive. Finally, a careful comparison of the present results with experimental values is carried out. (AU)

FAPESP's process: 17/21199-0 - The differentiable manifolds of the electronic structure theory
Grantee:Yuri Alexandre Aoto
Support Opportunities: Research Grants - Young Investigators Grants
FAPESP's process: 18/14629-1 - Diatomic molecules containing cobalt and their excited states
Grantee:Matheus Morato Ferreira de Moraes
Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
FAPESP's process: 18/04617-6 - The differentiable manifolds of the electronic structure theory
Grantee:Yuri Alexandre Aoto
Support Opportunities: Scholarships in Brazil - Young Researchers