AI Article Synopsis
- The study highlights an unusual property of ice where substituting hydrogen with deuterium leads to an expansion, contrary to the typical expectation of volume contraction when mass increases.
- This anomaly is enhanced at higher temperatures, opposing the conventional theory which suggests these effects should diminish as temperature rises.
- Using advanced theoretical modeling, the researchers successfully explain this behavior and also predict that replacing regular oxygen (16O) with a heavier isotope (18O) results in normal lattice contraction, which is confirmed through experiments.
Article Abstract
One striking anomaly of water ice has been largely neglected and never explained. Replacing hydrogen (1H) by deuterium (2H) 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 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 16O by 18O causes a normal lattice contraction.
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| http://dx.doi.org/10.1103/PhysRevLett.108.193003 | DOI Listing |
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