Anharmonic Properties of Aluminum from Direct Free Energy Interpolation Method

We compare the direct free energy interpolation（DFEI） method and the quasi-harmonic approximation（QHA） in calculating of the equation of states and thermodynamic properties of prototype Al. The Gibbs free energy of Al is calculated using the DFEI method based on the high-temperature phonon density o...

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Bibliographic Details
Published inCommunications in theoretical physics Vol. 67; no. 5; pp. 590 - 594
Main Author 赵志国 孙俊生 张修路 杨海峰 刘中利
Format Journal Article
LanguageEnglish
Published 01.05.2017
Subjects
信息披露
分子动力学模拟
吉布斯自由能
插值法
热力学性质
热膨胀系数
特性
铝
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ISSN0253-6102
DOI10.1088/0253-6102/67/5/590

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Summary:We compare the direct free energy interpolation（DFEI） method and the quasi-harmonic approximation（QHA） in calculating of the equation of states and thermodynamic properties of prototype Al. The Gibbs free energy of Al is calculated using the DFEI method based on the high-temperature phonon density of states reduced from classical molecular dynamics simulations. Then, we reproduce the thermal expansion coefficients, the specific heat, the isothermal bulk modulus of Al accurately. By comparing the results from the DFEI method and the QHA, we find that the DFEI method is indeed more accurate in calculating anharmonic properties than the QHA.
Bibliography:anharmonic effects high-pressure molecular dynamics
Zhi-Guo Zhao1, Jun-Sheng Sun2, Xiu-Lu Zhang3, Hai-Feng Yang1, Zhong-Li Liu1 （ 1College of Physics and Electric Information, Luoyang Normal University, Luoyang 471022, China 2The Unit 63615 of People＇s Liberation Army, Kuerle 841001, China 3Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology, Mianyang 621010, China）
11-2592/O3
We compare the direct free energy interpolation（DFEI） method and the quasi-harmonic approximation（QHA） in calculating of the equation of states and thermodynamic properties of prototype Al. The Gibbs free energy of Al is calculated using the DFEI method based on the high-temperature phonon density of states reduced from classical molecular dynamics simulations. Then, we reproduce the thermal expansion coefficients, the specific heat, the isothermal bulk modulus of Al accurately. By comparing the results from the DFEI method and the QHA, we find that the DFEI method is indeed more accurate in calculating anharmonic properties than the QHA.
ISSN:0253-6102
DOI:10.1088/0253-6102/67/5/590