标题： 从头算的水的熵计算预测天王星和海王星的内部比之前模型冷15-30% 显示英文标题

标题： Ab Initio Entropy Calculations of Water Predict the Interiors of Uranus and Neptune to be 15-30% Colder than Previous Models

摘要： 通过从头算自由能计算，在天王星和海王星内部的广泛条件下推导出液态和超离子态水的熵。 结果得到的绝热曲线在压力-温度空间中比之前用于天王星和海王星模型的要平坦得多。 因此，我们的模型中内部温度更低，增加了在冰巨星地幔中发生钻石雨或最近预测的行星冰相分离的可能性。 基于我们的从头算数据，我们使用同心麦卡洛林椭球法构建了与现有重力测量相匹配的天王星和海王星内部模型。 我们将全对流模型与包含液态和超离子态水之间对流边界模型进行比较。 我们还提供了一个用于表征巨行星大气的代码，其中包含正氢和仲氢以及氦的存在。 显示英文摘要

摘要： Ab initio free energy calculations are employed to derive the entropy of liquid and superionic water over a wide range of conditions in the interiors of Uranus and Neptune. The resulting adiabats are much shallower in pressure-temperature space than those adopted for earlier models of Uranus and Neptune. Our models for their interiors are thus much colder, increasing the likelihood that diamond rain or the recently predicted phase separation of planetary ices has occurred in the mantles of ice giant planets. Based on our ab initio data, we construct interior models for Uranus and Neptune with the Concentric MacLaurin Spheroid method that match the existing gravity measurements. We compare fully convective models with models that include a convective boundary between liquid and superionic water. We also share a code to characterize giant planet atmospheres where para and ortho hydrogen as well as helium are present.