Determination of Phonon Density of States from Constant-Pressure Heat Capacity Data of Soft Organic Materials in the Glassy and Crystalline States by Using the Real-Coded Genetic Algorithm.
Determination of Phonon Density of States from Constant-Pressure Heat Capacity Data of Soft Organic Materials in the Glassy and Crystalline States by Using the Real-Coded Genetic Algorithm.
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利用实数编码遗传算法根据玻璃态和晶态软有机材料的恒压热容数据确定声子态密度。
DOI：
10.1021/acs.jpcb.0c06666
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
M. Tamura
中科院分区：
文献类型：
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作者：
K. Ueda;Chie Morikawa;M. Oguni;Minami Kato;M. Tamura
提出了一种基于纯代隙+实数编码交叉的实数编码遗传算法（RCGA），由材料的热容数据计算其声子态密度[g（ω）]的方法.通过分析由德拜和光学模式组成的初始假设模型g 0（ω）评估的热容数据集，测试RCGA是否再现合理的g（ω），从而证实了该方法的性能。作为一个例子，测量了软分子材料磷酸二苯酯（DPP）和二苯基次膦酸在凝聚态下的恒压热容（CPs），并通过应用RCGA从CP数据确定了它们的g（ω）s。在DPP中观察到玻璃的CP值在10 - 70 K温度范围内小于晶体的CP值的异常行为;与晶体相比，玻璃的行为与通常预期的相反。用RCGA测定了玻璃的g（ω）s，结果表明，玻璃的g（ω）比晶体蓝移了30-240 K。通过密度泛函理论计算，确定了DPP分子内强、弱氢键的振动，合理地讨论了蓝移等效应源于DPP分子内强、弱氢键的竞争共存.结果表明，RCGA方法对于从精确的热容数据中获取g（ω）的微观信息以及研究不同相材料g（ω）s的细节差异具有重要的应用价值。
A method was proposed to derive the phonon density [g(ω)] of states of materials from their heat capacity data by using Real-Coded Genetic Algorithm (RCGA) with Just Generation Gap + Real-Coded Ensemble Crossover. The performance of the method was confirmed by testing whether or not the RCGA reproduces a reasonable g(ω) by analyzing the set of heat capacity data evaluated from an initially assumed model g0(ω) composed of Debye and optical modes. As an example, constant-pressure heat capacities (CPs) were measured for soft molecular materials, diphenyl phosphate (DPP) and diphenylphosphinic acid, in the condensed state, and their g(ω)s were determined from the CP data by applying the RCGA. The unusual behavior that the CP value of glass was smaller than the one of the crystal in the temperature range from 10 to 70 K was observed in DPP; the behavior is contrary to that expected ordinarily for the glass as compared with the crystal. The g(ω)s determined by the RCGA demonstrated that the unusual behavior was attributed to the blue shift in g(ω) of ω = 30-240 K in the glass compared with the crystal. The blue shift and other effects were discussed reasonably as originating from the competitive concurrence of strong and weak intermolecular hydrogen bonds in DPP, with the help of determination of their intramolecular vibrations for the isolated molecule by the density functional theory calculation. It was concluded that the method using the RCGA is of value for obtaining the microscopic information of g(ω) from the precise heat capacity data and for investigating any difference between the details of g(ω)s in different phases of materials.
4-二甲氨基-N-甲基-4-芪唑鎓甲苯磺酸盐远红外吸收光谱的第一性原理计算
DOI：
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发表时间：
2006
期刊：
Chemical Physics Letters 432
影响因子：
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作者：
斉藤 繁喜
通讯作者：
斉藤 繁喜