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将平均原子模型和密度泛函理论相结合,发展了一个计算高温稠密等离子体中离子之间平均相互作用势的理论模型. 利用平均原子模型考虑了高温稠密物质中电子的激发和密度效应对电子结构的影响,利用动能和交换相关能的局域密度泛函近似计算离子之间的平均相互作用. 基于发展的相互作用势模型,开展了分子动力学模拟,研究了高温稠密Al和Fe等离子体的状态方程. 相似文献
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在改进的Hartree-Fock-Slater原子模型的基础上,在中心场近似下用含能带效应的全动态电子判据处理自由电子与束缚电子的密度分布,提高了电子波函数、电子占据数等原子参数的计算精度.通过平均近似处理,给出了劈裂的能带,从而改善了物质电子状态方程的计算精度.结果部分详细计算了W元素的原子能量、电子压强、熵、定容热容及其它热力学参数 相似文献
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在改进的Hartree-Fock-Slater原子模型的基础上,在中心场近似下用含能带效应的全动态电子判据处理自由电子与束缚电子的密度分布,提高了电子波函数、电子占据数等原子参数的计算精度.通过平均近似处理,给出了劈裂的能带,从而改善了物质电子状态方程的计算精度.结果部分详细计算了W元素的原子能量、电子压强、熵、定容热容及其它热力学参数 相似文献
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在改进的平均原子模型的基础上,在中心场近似下用分波法来处理部分自由电子密度分布函数,提高了电子波函数、电子占据数等原子参数的计算精度.通过平均近似处理,给出了劈裂的能带.通过使用分波法来准确计算贵金属Au的电子状态方程. 相似文献
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本文采用球元胞、中心力场、相对论费米统计近似,通过自洽场方法,应用平均原子模型计算了热稠密物质硅的类氖离子能级ZS→2P跃迁及其状态方程。 相似文献
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本文采用球元胞、中心力场、相对论费米统计近似,通过自洽场方法,应用平均原子模型计算了热稠密物质硅的类氖离子能级2S→2P跃迁及其状态方程。 相似文献
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Effect of radiation on compressibility of hot dense sodium and iron plasma using improved screened hydrogenic model with l splitting 下载免费PDF全文
《中国物理 B》2021,(3)
High pressure investigations of matter involve the study of strong shock wave dynamics within the materials which gives rise to many thermal effects leading to dissociation of molecules, ionization of atoms, and radiation emission, etc.The response of materials experiencing a strong shock can be determined by its shock Hugoniot calculations which are frequently applied in numerical and experimental studies in inertial confinement fusion, laboratory astrophysical plasma,etc. These studies involve high energy density plasmas in which the radiation plays an important role in determining the energy deposition and maximum compressibility achieved by the shock within material. In this study, we present an investigation for the effect of radiation pressure on the maximum compressibility of the material using shock Hugoniot calculations. In shock Hugoniot calculations, an equation of state(EOS) is developed in which electronic contributions for EOS calculations are taken from an improved screened hydrogenic model with-l splitting(I-SHML) [High Energy Density Physics(2018) 26 48] under local thermodynamic equilibrium(LTE) conditions. The thermal ionic part calculations are adopted from the state of the art Cowan model while the cold ionic contributions are adopted from the scaled binding energy model. The Shock Hugoniot calculations are carried out for sodium and iron plasmas and our calculated results show excellent agreement with published results obtained by using either sophisticated self-consistent models or the first principle study. 相似文献
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派热克斯玻璃的Hugoniot实验数据显示了在20GPa以下存在相变,我们认为这是一种固态-固态的一级相变,根据Gibbs相平衡条件并应用了相变前的低压物态方程,计算了这种固态-固态相变的熵增。计算表明熵增为负值,即相变为放热过程。在此基础上给出了相变区的物态方程,其中冷压为平台,内能计入了相变熵的影响。由相变区的物态方程得到的理论的与实验的Hugoniot曲线基本一致。 相似文献
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��ҫ�£������ԣ��� 《核聚变与等离子体物理》2015,35(3):198-203
The cold pressure parameters of q and Q in the Born-Mayer(BM) model for fifty-seven metals equations were calculated by using the Hu-Jing(HJ) method based on isothermal bulk moduli of metal and measured data in shock wave experiments, and at the same time a trial method for computing them by combining Thomas-Fermi model at absolute zero-temperature with low pressure experiment data, is put forward for lack of the sufficient shock wave experiment data. By integrating the Faussurier model for electron thermal pressure, the Cowan model for ion thermal pressure and the above obtained cold pressure fitted formula, the Hugoniot curves of Be, Co and Pb are calculated and compared with experimental data, and then the discrepancies of q value and Q value obtained by HJ method and a comprehensive method are analyzed and interpreted. Furthermore, the precision for the cold pressure equation by HJ method is assessed by comparing the thermodynamic quantities on the Hugoniot curves of Sr, Ba, and Sm with the corresponding measured results and the calculated ones by other models. 相似文献
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Abstract First principle predictions for the equation of state of gold using solid and liquid state theories are compared up to combined pressures and temperatures of 600 GPa and 17 000 K with static diamond anvil cell compression, ultrasonic measurements and shock Hugoniot data which include a recent laser driven shock Hugoniot points at 600 GPa. Excellent agreement between theoretical and experimental data is observed. The theoretically estimated 300 K isotherm agrees to within 2 GPa with the isotherm that has been measured to 70 GPa using the diamond anvil cell. The structural energy estimates show that the normal f.c.c. phase remains stable under pressure. The estimate of the shock Hugoniot temperature of gold at 600 GPa based on a liquid state model is consistent with the measurements of laser induced shock luminescence, which in fact provides an experimental determination of the temperature of gold above its Hugoniot melting point. The powerful means provided by theory in the prediction of material properties of gold at ultra high pressures and temperatures is significant because gold is an efficient converter of laser energy into soft X-rays and is a potential candidate as a standard for high pressure, high temperature work. 相似文献
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A five-parameter equation of state (EOS) is proposed, which correctly incorporates the cohesive energy data without physically incorrect oscillations in both extreme high pressure and expansion regions. Based on a modified Einstein model, the thermal effect is included in the proposed EOS complying with the zero-pressure condition. With this thermal EOS applied to five solids (Ar, Al, Au, Cu and Li), some important thermodynamic properties as isotherm, isochore, thermal expansion coefficient, volume modulus, heat capacity and Hugoniot are calculated for each selected solid with good agreement with experimental data, which confirms the validity of the present work 相似文献
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使用第一性原理方法结合平均场模型研究了压力从0到150GPa、温度从0到1500K,金属铍六角密排结构(hcp)的热力学性质,包括铍的常态性质,等温高压物态方程,以及常压下平衡体积、体弹模量随温度的变化,Hugoniot曲线等.0K物态方程由广义梯度近似下的密度泛函理论计算,粒子热运动的贡献由平均场模型计算.由于铍的Debye温度比较高,计算自由能时考虑了零点振动能修正.计算结果与已有的静力学和冲击波实验数据符合得非常好.
关键词:
热力学性质
物态方程
第一原理计算 相似文献