Semiclassical and VSCF/VCI Calculations of the Vibrational Energies of trans- and gauche-Ethanol Using a CCSD(T) Potential Energy Surface
Articolo
Data di Pubblicazione:
2022
Citazione:
Semiclassical and VSCF/VCI Calculations of the Vibrational Energies of trans- and gauche-Ethanol Using a CCSD(T) Potential Energy Surface / R. Conte, A. Nandi, C. Qu, Q. Yu, P.L. Houston, J.M. Bowman. - In: JOURNAL OF PHYSICAL CHEMISTRY. A, MOLECULES, SPECTROSCOPY, KINETICS, ENVIRONMENT, & GENERAL THEORY. - ISSN 1089-5639. - 126:42(2022 Oct 27), pp. 7709-7718. [10.1021/acs.jpca.2c06322]
Abstract:
A recent full-dimensional Delta-Machine learning potential energy surface (PES) for ethanol is employed in semiclassical and vibrational self-consistent field (VSCF) and virtual-state configuration interaction (VCI) calculations, using MULTIMODE, to determine the anharmonic vibrational frequencies of vibration for both the trans and gauche conformers of ethanol. Both semiclassical and VSCF/VCI energies agree well with the experimental data. We find significant mixing between the VSCF basis states due to Fermi resonances between bending and stretching modes. The same effects are also accurately described by the full-dimensional semiclassical calculations. These are the first high-level anharmonic calculations using a PES, in particular a "gold-standard" CCSD(T) one.
Tipologia IRIS:
01 - Articolo su periodico
Elenco autori:
R. Conte, A. Nandi, C. Qu, Q. Yu, P.L. Houston, J.M. Bowman
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