TY - JOUR
T1 - Nature of the Volume Isotope Effect in Ice
AU - Umemoto, Koichiro
AU - Sugimura, Emiko
AU - De Gironcoli, Stefano
AU - Nakajima, Yoichi
AU - Hirose, Kei
AU - Ohishi, Yasuo
AU - Wentzcovitch, Renata M.
N1 - Publisher Copyright:
© 2015 American Physical Society.
PY - 2015/10/22
Y1 - 2015/10/22
N2 - The substitution of hydrogen (H) by deuterium (D) in ice Ih and in its H-ordered version, ice XI, produces an anomalous form of volume isotope effect (VIE), i.e., volume expansion. This VIE contrasts with the normal VIE (volume contraction) predicted in ice-VIII and in its H-disordered form, ice VII. Here we investigate the VIE in ice XI and in ice VIII using first principles quasiharmonic calculations. We conclude that normal and anomalous VIEs can be produced in ice VIII and ice XI in sequence by application of pressure (ice XI starting at negative pressures) followed by a third type - anomalous VIE with zero-point volume contraction. The latter should also contribute to the isotope effect in the ice VII → ice X transition. The predicted change between normal and anomalous VIE in ice VIII at 14.3 GPa and 300 K is well reproduced experimentally in ice VII using x-ray diffraction measurements. The present discussion of the VIE is general, and conclusions should be applicable to other solid phases of H2O, possibly to liquid water under pressure, and to other H-bonded materials.
AB - The substitution of hydrogen (H) by deuterium (D) in ice Ih and in its H-ordered version, ice XI, produces an anomalous form of volume isotope effect (VIE), i.e., volume expansion. This VIE contrasts with the normal VIE (volume contraction) predicted in ice-VIII and in its H-disordered form, ice VII. Here we investigate the VIE in ice XI and in ice VIII using first principles quasiharmonic calculations. We conclude that normal and anomalous VIEs can be produced in ice VIII and ice XI in sequence by application of pressure (ice XI starting at negative pressures) followed by a third type - anomalous VIE with zero-point volume contraction. The latter should also contribute to the isotope effect in the ice VII → ice X transition. The predicted change between normal and anomalous VIE in ice VIII at 14.3 GPa and 300 K is well reproduced experimentally in ice VII using x-ray diffraction measurements. The present discussion of the VIE is general, and conclusions should be applicable to other solid phases of H2O, possibly to liquid water under pressure, and to other H-bonded materials.
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U2 - 10.1103/PhysRevLett.115.173005
DO - 10.1103/PhysRevLett.115.173005
M3 - Article
C2 - 26551113
AN - SCOPUS:84945583086
SN - 0031-9007
VL - 115
JO - Physical review letters
JF - Physical review letters
IS - 17
M1 - 173005
ER -