Instituto de Ciencia de Materiales, Consejo Superior de Investigaciones Científicas (CSIC), Campus de Cantoblanco, 28049 Madrid, Spain.
J Chem Phys. 2011 Mar 7;134(9):094510. doi: 10.1063/1.3559466.
Ice Ih has been studied by path-integral molecular dynamics simulations, using the effective q-TIP4P/F potential model for flexible water. This has allowed us to analyze finite-temperature quantum effects in this solid phase from 25 to 300 K at ambient pressure. Among these effects we find a negative thermal expansion of ice at low temperatures, which does not appear in classical molecular dynamics simulations. The compressibility derived from volume fluctuations gives results in line with experimental data. We have analyzed isotope effects in ice Ih by considering normal, heavy, and tritiated water. In particular, we studied the effect of changing the isotopic mass of hydrogen on the kinetic energy and atomic delocalization in the crystal as well as on structural properties such as interatomic distances and molar volume. For D(2)O ice Ih at 100 K we obtained a decrease in molar volume and intramolecular O-H distance of 0.6% and 0.4%, respectively, as compared to H(2)O ice.
冰 Ih 已通过路径积分分子动力学模拟进行了研究，使用了用于柔性水的有效 q-TIP4P/F 势能模型。这使我们能够在环境压力下从 25 到 300 K 的温度范围内分析该固相中的有限温度量子效应。在这些效应中，我们发现冰在低温下存在负热膨胀，而这在经典分子动力学模拟中并未出现。从体积波动得出的压缩系数给出了与实验数据相符的结果。我们通过考虑普通、重水和氚化水研究了冰 Ih 的同位素效应。特别地，我们研究了改变氢的同位素质量对晶体中动能和原子离域的影响，以及对原子间距离和摩尔体积等结构性质的影响。对于 100 K 的 D(2)O 冰 Ih，与 H(2)O 冰相比，摩尔体积和分子内 O-H 距离分别减少了 0.6%和 0.4%。
