0599916 - ÚFCH JH 2025 RIV US eng J - Journal Article
Višňák, Jakub - Brandejs, Jan - Maté, M. - Visscher, L. - Legeza, Ö. - Pittner, Jiří
DMRG-Tailored Coupled Cluster Method in the 4c-Relativistic Domain: General Implementation and Application to the NUHFI and NUFsub3/sub Molecules.
Journal of Chemical Theory and Computation. Roč. 20, č. 20 (2024), s. 8862-8875. ISSN 1549-9618. E-ISSN 1549-9626
R&D Projects: GA ČR(CZ) GA18-24563S; GA MŠMT EH22_008/0004558
Research Infrastructure: e-INFRA CZ II - 90254
Institutional support: RVO:61388955
Keywords : matrix renormalization-group * electron correlation * quantum-chemistry * state * single * symmetry * models
OECD category: Physical chemistry
Impact factor: 5.7, year: 2023 ; AIS: 1.419, rok: 2023
Method of publishing: Open access
DOI: https://doi.org/10.1021/acs.jctc.4c00641

Heavy atom compounds represent a challenge for computational chemistry due to the need for simultaneous treatment of relativistic and correlation effects. Often such systems also exhibit strong correlation, which hampers the application of perturbation theory or single-reference coupled cluster (CC) methods. As a viable alternative, we have proposed externally correcting the CC method using the density matrix renormalization group (DMRG) wave functions, yielding the DMRG-tailored CC method. In a previous paper [J. Chem. Phys. 2020, 152, 174107], we reported a first implementation of this method in the relativistic context, which was restricted to molecules with real double group symmetry. In this work, we present a fully general implementation of the method, covering complex and quaternion double groups as well. The 4c-TCC method thus becomes applicable to polyatomic molecules, including heavy atoms. For the assessment of the method, we performed calculations of the chiral uranium compound NUHFI, which was previously studied in the context of the enhancement of parity violation effects. In particular, we performed calculations of a cut of the potential energy surface of this molecule along the stretching of the N-U bond, where the system exhibits strong multireference character. Since there are no experimental data for NUHFI, we have performed also an analogous study of the (more symmetric) NUF3 molecule, where the vibrational frequency of the N-U bond can be compared with spectroscopic data.
Permanent Link: https://hdl.handle.net/11104/0357327