TY - JOUR
T1 - Nuclear quantum effects of light and heavy water studied by all-electron first principles path integral simulations
AU - Machida, Masahiko
AU - Kato, Koichiro
AU - Shiga, Motoyuki
N1 - Funding Information:
The simulations were performed on FUJITSU PRIMERGY BX900 and SGI ICE X supercomputers in CCSE JAEA. The authors thank CCSE staff members for their support. M.S. thanks the support from JSPS KAKEKHI Grant No. 16K05675. M.M. also thanks the support from JSPS KAKENHI Grant Nos. 16H04624, 16H02450, 16H02437, and 15K00718. M.M. is indebted to K. Sakuramoto and H. Nakamura for their technical support in using VASP. All authors are grateful to Dr. A. Malins in JAEA for proofreading the manuscript of this paper.
PY - 2018/3/14
Y1 - 2018/3/14
N2 - The isotopologs of liquid water, H2O, D2O, and T2O, are studied systematically by first principles PIMD simulations, in which the whole entity of the electrons and nuclei are treated quantum mechanically. The simulation results are in reasonable agreement with available experimental data on isotope effects, in particular, on the peak shift in the radial distributions of H2O and D2O and the shift in the evaporation energies. It is found that, due to differences in nuclear quantum effects, the H atoms in the OH bonds more easily access the dissociative region up to the hydrogen bond center than the D (T) atoms in the OD (OT) bonds. The accuracy and limitation in the use of the current density-functional-theory-based first principles PIMD simulations are also discussed. It is argued that the inclusion of the dispersion correction or relevant improvements in the density functionals are required for the quantitative estimation of isotope effects.
AB - The isotopologs of liquid water, H2O, D2O, and T2O, are studied systematically by first principles PIMD simulations, in which the whole entity of the electrons and nuclei are treated quantum mechanically. The simulation results are in reasonable agreement with available experimental data on isotope effects, in particular, on the peak shift in the radial distributions of H2O and D2O and the shift in the evaporation energies. It is found that, due to differences in nuclear quantum effects, the H atoms in the OH bonds more easily access the dissociative region up to the hydrogen bond center than the D (T) atoms in the OD (OT) bonds. The accuracy and limitation in the use of the current density-functional-theory-based first principles PIMD simulations are also discussed. It is argued that the inclusion of the dispersion correction or relevant improvements in the density functionals are required for the quantitative estimation of isotope effects.
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U2 - 10.1063/1.5000091
DO - 10.1063/1.5000091
M3 - Article
C2 - 29544339
AN - SCOPUS:85037675656
VL - 148
JO - Journal of Chemical Physics
JF - Journal of Chemical Physics
SN - 0021-9606
IS - 10
M1 - 102324
ER -