标题： 冰 Ih 中的同位素效应：路径积分模拟 显示英文标题

标题： Isotope effects in ice Ih: A path-integral simulation

摘要： 冰 Ih 通过路径积分分子动力学模拟进行了研究，使用了有效的 q-TIP4P/F 势模型来描述柔性水。 这使我们能够在常压下从 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，我们发现低温下冰的负热膨胀，这在经典分子动力学模拟中并未出现。 从体积涨落得出的压缩率与实验数据一致。 我们通过考虑普通、重和氚化水来分析冰 Ih 中的同位素效应。 特别是，我们研究了氢同位素质量变化对晶体中动能和原子离域的影响，以及对结构特性如原子间距离和摩尔体积的影响。 对于 100 K 下的 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%。 显示英文摘要

摘要： 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.