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arXiv · 1111.4870

Anomalous Nuclear Quantum Effects in Ice

B. Pamuk·J. M. Soler·R. Ramirez·C. P. Herrero·P. W. Stephens·P. B. Allen·M. V. Fernandez-Serra
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Abstract

One striking anomaly of water ice has been largely neglected and never explained. Replacing hydrogen ($^1$H) by deuterium ($^2$H) causes ice to expand, whereas the "normal" isotope effect is volume contraction with increased mass. Furthermore, the anomaly increases with temperature $T$, even though a normal isotope shift should decrease with $T$ and vanish when $T$ is high enough to use classical nuclear motions. In this study, we show that these effects are very well described by {\it ab initio} density functional theory. Our theoretical modeling explains these anomalies, and allows us to predict and to experimentally confirm a counter effect, namely that replacement of $^{16}$O by $^{18}$O causes a normal lattice contraction.

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B. Pamuk, J. M. Soler, R. Ramirez, C. P. Herrero, P. W. Stephens, P. B. Allen, M. V. Fernandez-Serra. 2011-11-21. Anomalous Nuclear Quantum Effects in Ice. https://doi.org/10.1103/physrevlett.108.193003

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