Weck Philippe F, Kim Eunja
Sandia National Laboratories, Albuquerque, NM 87185, USA.
Dalton Trans. 2014 Dec 7;43(45):17191-9. doi: 10.1039/c4dt02455a.
The structure of dehydrated schoepite, α-UO2(OH)2, was investigated using computational approaches that go beyond standard density functional theory and include van der Waals dispersion corrections (DFT-D). Thermal properties of α-UO2(OH)2, were also obtained from phonon frequencies calculated with density functional perturbation theory (DFPT) including van der Waals dispersion corrections. While the isobaric heat capacity computed from first-principles reproduces available calorimetric data to within 5% up to 500 K, some entropy estimates based on calorimetric measurements for UO3·0.85H2O were found to overestimate by up to 23% the values computed in this study.
使用超越标准密度泛函理论并包含范德华色散校正（DFT-D）的计算方法，对脱水柱铀矿α-UO₂(OH)₂的结构进行了研究。α-UO₂(OH)₂的热性质也通过密度泛函微扰理论（DFPT）计算的声子频率获得，该理论包含范德华色散校正。虽然从第一性原理计算得到的等压热容在500 K以下能将现有量热数据重现至5%以内，但发现一些基于UO₃·0.85H₂O量热测量的熵估计值比本研究计算的值高估了23%。
