Nuclear quantum effects on the structure and the dynamics of [H 2O]8 at low temperatures
We use ring-polymer-molecular-dynamics (RPMD) techniques and the semi-empirical q-TIP4P/F water model to investigate the relationship between hydrogen bond connectivity and the characteristics of nuclear position fluctuations, including explicit incorporation of quantum effects, for the energeticall...
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00219606_v139_n17_p_Videla http://hdl.handle.net/20.500.12110/paper_00219606_v139_n17_p_Videla |
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paper:paper_00219606_v139_n17_p_Videla2023-06-08T14:44:24Z Nuclear quantum effects on the structure and the dynamics of [H 2O]8 at low temperatures Videla, Pablo Ernesto Collective dynamics Connectivity pattern Instantaneous normal modes Intermolecular distance Many-body potentials Nuclear quantum effects Polarization fluctuations Spatial delocalization Absorption spectroscopy Dangling bonds Hydrogen bonds Isomers Light absorption Molecular dynamics Quantum electronics We use ring-polymer-molecular-dynamics (RPMD) techniques and the semi-empirical q-TIP4P/F water model to investigate the relationship between hydrogen bond connectivity and the characteristics of nuclear position fluctuations, including explicit incorporation of quantum effects, for the energetically low lying isomers of the prototype cluster [H2O] 8 at T = 50 K and at 150 K. Our results reveal that tunneling and zero-point energy effects lead to sensible increments in the magnitudes of the fluctuations of intra and intermolecular distances. The degree of proton spatial delocalization is found to map logically with the hydrogen-bond connectivity pattern of the cluster. Dangling hydrogen bonds exhibit the largest extent of spatial delocalization and participate in shorter intramolecular O-H bonds. Combined effects from quantum and polarization fluctuations on the resulting individual dipole moments are also examined. From the dynamical side, we analyze the characteristics of the infrared absorption spectrum. The incorporation of nuclear quantum fluctuations promotes red shifts and sensible broadening relative to the classical profile, bringing the simulation results in much more satisfactory agreement with direct experimental information in the mid and high frequency range of the stretching band. While RPMD predictions overestimate the peak position of the low frequency shoulder, the overall agreement with that reported using an accurate, parameterized, many-body potential is reasonable, and far superior to that one obtains by implementing a partially adiabatic centroid molecular dynamics approach. Quantum effects on the collective dynamics, as reported by instantaneous normal modes, are also discussed. © 2013 AIP Publishing LLC. Fil:Videla, P.E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2013 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00219606_v139_n17_p_Videla http://hdl.handle.net/20.500.12110/paper_00219606_v139_n17_p_Videla |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Collective dynamics Connectivity pattern Instantaneous normal modes Intermolecular distance Many-body potentials Nuclear quantum effects Polarization fluctuations Spatial delocalization Absorption spectroscopy Dangling bonds Hydrogen bonds Isomers Light absorption Molecular dynamics Quantum electronics |
| spellingShingle |
Collective dynamics Connectivity pattern Instantaneous normal modes Intermolecular distance Many-body potentials Nuclear quantum effects Polarization fluctuations Spatial delocalization Absorption spectroscopy Dangling bonds Hydrogen bonds Isomers Light absorption Molecular dynamics Quantum electronics Videla, Pablo Ernesto Nuclear quantum effects on the structure and the dynamics of [H 2O]8 at low temperatures |
| topic_facet |
Collective dynamics Connectivity pattern Instantaneous normal modes Intermolecular distance Many-body potentials Nuclear quantum effects Polarization fluctuations Spatial delocalization Absorption spectroscopy Dangling bonds Hydrogen bonds Isomers Light absorption Molecular dynamics Quantum electronics |
| description |
We use ring-polymer-molecular-dynamics (RPMD) techniques and the semi-empirical q-TIP4P/F water model to investigate the relationship between hydrogen bond connectivity and the characteristics of nuclear position fluctuations, including explicit incorporation of quantum effects, for the energetically low lying isomers of the prototype cluster [H2O] 8 at T = 50 K and at 150 K. Our results reveal that tunneling and zero-point energy effects lead to sensible increments in the magnitudes of the fluctuations of intra and intermolecular distances. The degree of proton spatial delocalization is found to map logically with the hydrogen-bond connectivity pattern of the cluster. Dangling hydrogen bonds exhibit the largest extent of spatial delocalization and participate in shorter intramolecular O-H bonds. Combined effects from quantum and polarization fluctuations on the resulting individual dipole moments are also examined. From the dynamical side, we analyze the characteristics of the infrared absorption spectrum. The incorporation of nuclear quantum fluctuations promotes red shifts and sensible broadening relative to the classical profile, bringing the simulation results in much more satisfactory agreement with direct experimental information in the mid and high frequency range of the stretching band. While RPMD predictions overestimate the peak position of the low frequency shoulder, the overall agreement with that reported using an accurate, parameterized, many-body potential is reasonable, and far superior to that one obtains by implementing a partially adiabatic centroid molecular dynamics approach. Quantum effects on the collective dynamics, as reported by instantaneous normal modes, are also discussed. © 2013 AIP Publishing LLC. |
| author |
Videla, Pablo Ernesto |
| author_facet |
Videla, Pablo Ernesto |
| author_sort |
Videla, Pablo Ernesto |
| title |
Nuclear quantum effects on the structure and the dynamics of [H 2O]8 at low temperatures |
| title_short |
Nuclear quantum effects on the structure and the dynamics of [H 2O]8 at low temperatures |
| title_full |
Nuclear quantum effects on the structure and the dynamics of [H 2O]8 at low temperatures |
| title_fullStr |
Nuclear quantum effects on the structure and the dynamics of [H 2O]8 at low temperatures |
| title_full_unstemmed |
Nuclear quantum effects on the structure and the dynamics of [H 2O]8 at low temperatures |
| title_sort |
nuclear quantum effects on the structure and the dynamics of [h 2o]8 at low temperatures |
| publishDate |
2013 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00219606_v139_n17_p_Videla http://hdl.handle.net/20.500.12110/paper_00219606_v139_n17_p_Videla |
| work_keys_str_mv |
AT videlapabloernesto nuclearquantumeffectsonthestructureandthedynamicsofh2o8atlowtemperatures |
| _version_ |
1768545359155429376 |