Competitive nuclear quantum effect and H/D isotope effect on torsional motion of H2O2: An ab initio path integral molecular dynamics study

Udagawa, Taro; Kuwahata, Kazuaki; Tachikawa, Masanori

doi:10.1016/j.comptc.2021.113542

Cited by 4 publications

(3 citation statements)

References 40 publications

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“…3 Path integral molecular dynamics (PIMD), [4][5][6] centroid molecular dynamics (CMD), [7][8][9] and ring polymer molecular dynamics (RPMD) [10][11][12] methods and their variants have been applied to wide variety of systems. [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] The present work explores the NQEs in 2-fluoroethanol (2FE). As part of the set of 2-X-ethanols (X=F, Cl, OH, NH 2 ), 2FE has been well-explored from both experiments and theory with regard to its various conformations, intramolecular interactions (whether there is an intramolecular O-H• • • F H-bond and its strength) and spectroscopy [28][29][30][31][32][33][34][35][36] as well as conformational isomerization upon CH or OH excitation and the intramolecular vibrational energy redistribution that drives it.…”

Section: Introductionmentioning

confidence: 99%

Nuclear Quantum Effects in Gas-Phase 2-Fluoroethanol

Arandhara,

Ramesh

2023

Preprint

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Torsional motions along the FCCO and HOCC dihedrals lead to the five unique conformations of 2-fluoroethanol. In this work, we explore how nuclear quantum effects (NQEs) are manifest in the intramolecular landscape along these two dihedrals, through the use of path integral simulations. We have first developed a full dimensional potential energy surface using the reaction surface Hamiltonian framework. On this potential, we have carried out path integral molecular dynamics at several temperatures starting from the minimum energy well to explore structural influences of NQEs. With umbrella sampling and metadynamics simulations at 300 K and 50 K, we have explored whether NQEs have effects on the free energy landscape. Significant influences are found near the cis region of the dihedrals, which can be understood through the trends in the radii of gyration of the atomic ring polymers. We have also computed the infrared spectra at 300 K and 50 K with thermostatted ring polymer molecular dynamics simulations, which agrees well with experimental band positions.

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Section: Introductionmentioning

confidence: 99%

Nuclear Quantum Effects in Gas-Phase 2-Fluoroethanol

Arandhara,

Ramesh

2023

Preprint

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“…PIMD can also consider NQEs statistically within the Born–Oppenheimer approximation framework. 11 − 13 , 17 − 24 The PIMD approach considers NQEs as well as thermal effects. Many PIMD studies have been used to understand NQEs in the context of hydrogen-bonded systems, including LBHBs.…”

Section: Introductionmentioning

confidence: 99%

“…We used MC_MO methods to successfully evaluate the effects of NQEs and H/D isotopes in different hydrogen-bonded systems and proton transfer reactions. PIMD can also consider NQEs statistically within the Born–Oppenheimer approximation framework. − ,− The PIMD approach considers NQEs as well as thermal effects. Many PIMD studies have been used to understand NQEs in the context of hydrogen-bonded systems, including LBHBs.…”

Section: Introductionmentioning

confidence: 99%

Low-Barrier Hydrogen Bond in Fujikurin A–D: A Computational Study

et al. 2022

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The compounds Fujikurin A, B, and D, recently isolated from Fusarium fujikuroi , possess intramolecular low-barrier hydrogen bonds (LBHBs), which are hydrogen bonds with a very low-energy barrier for proton transfer. The isolated compounds have a hydrogen-bonded proton that appears to rapidly switch between two equilibrium states via a transition state (TS). To understand the characteristics of these intramolecular LBHBs in detail, we performed path integral molecular dynamics (PIMD) simulations, which can consider nuclear quantum effects (NQEs) under a finite temperature. The PIMD simulations predicted that the NQE completely washed out the energy barrier for the proton transfer reaction. Consequently, a single-well shape emerged in the results, along with the effective free-energy potential surface for the hydrogen-bonded proton distribution. Thus, we conclude that the hydrogen-bonded proton in Fujikurin does not in fact transfer between two equilibrium structures but widely delocalizes around the global minimum structure involving the TS region.

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