Thermodynamic properties of CaCO3 calcite and aragonite: A quasi-harmonic calculation
Thermodynamic properties of CaCO3 calcite and aragonite: A quasi-harmonic calculation
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CaCO3 方解石和文石的热力学性质：准调和计算
DOI：
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发表时间：
1993
期刊：
影响因子：
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通讯作者：
G. D. Price
中科院分区：
文献类型：
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作者：
M. Catti;A. Pavese;G. D. Price
一个准谐波模型已被用来模拟的CaCO 3多晶型物的热力学行为，通过平衡它们的晶体结构作为温度的函数，以平衡对施加的外部压力的内部静态和热压力的总和。所需的振动频率和弹性性质已计算使用原子间势的基础上两体玻恩型功能，与O-C-O角项占共价内的CO 3分子离子。模拟的热容和熵与实验数据基本吻合，而热膨胀系数似乎更难再现。文石得到的结果是不太令人满意的方解石，但它们是通过使用该相本身的性能特别优化的潜力得到改善。
A quasi-harmonic model has been used to simulate the thermodynamic behaviour of the CaCO3 polymorphs, by equilibrating their crystal structures as a function of temperature so as to balance the sum of inner static and thermal pressures against the applied external pressure. The vibrational frequencies and elastic properties needed have been computed using interatomic potentials based on two-body Born-type functions, with O-C-O angular terms to account for covalency inside the CO3 molecular ion. A good agreement with experimental data is generally shown by simulated heat capacity and entropy, while the thermal expansion coefficient seems to be more difficult to reproduce. The results obtained for aragonite are less satisfactory than those of calcite, but they are improved by using a potential specifically optimized on properties of that phase itself.