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Please wait a minute... For Selected: Download Citations EndNote Ris BibTeX Toggle Thumbnails Select Quantum Molecular Dynamics Simulations of Transport Properties of Liquid Plutonium WANG Shuaichuang, ZHANG Gongmu, SUN Bo, SONG Haifeng, TIAN Mingfeng, FANG Jun, LIU Haifeng CHINESE JOURNAL OF COMPUTATIONAL PHYSICS    2019, 36 (3): 253-258.   DOI: 10.19596/j.cnki.1001-246x.7852 Abstract （444）   HTML （10）    PDF （3036KB）（1350）       Knowledge map    We studied transport properties of liquid Pu with quantum molecular dynamics (QMD) simulations. We focused on calculating viscosity and diffusion properties from autocorrelation function. Our results are in good agreement with experiment in the range of measurement. There is obvious difference between our results and reference at lower temperatures and they show good agreement at relatively higher temperatures. Structures of autocorrelation function of off-diagonal components of stress tensor (STACF) and velocity autocorrelation function (VACF) at lower temperatures are observed and they exhibit correlated liquid-like behavior. Extrapolating autocorrelation function in t→∞ limit leads to larger error for viscosity and diffusion coefficient of correlated liquid. We obtain accurate viscosity and diffusion coefficient of liquid Pu from long simulation trajectories. Reference | Related Articles | Metrics Select Application of Simulated Annealing Method in Chemical Free Energy Model LI Qiong, LIU Haifeng, ZHANG Gongmu, ZHANG Qili CHINESE JOURNAL OF COMPUTATIONAL PHYSICS    2019, 36 (3): 259-264.   DOI: 10.19596/j.cnki.1001-246x.7853 Abstract （297）   HTML （0）    PDF （3984KB）（1373）       Knowledge map    Application of simulated annealing method in chemical free energy model to search for chemical composition of equilibrium state is proposed. Due to the random "thermal" fluctuations introduced by simulated annealing method, the difficulty associated with sensitivity of result to initial values is removed. Moreover, in the regime of first order phase transition where stable state and meta-stable state coexist, the stable state can always be obtained. As an example, chemical free energy model improved by simulated annealing method is applied to the equation of state for fluid helium, which demonstrates the plasma phase transition induced by pressure ionization. Reference | Related Articles | Metrics Select Path Integral Monte Carlo Calculations of Equation of State of Hydrogen ZHANG Qili, LIU Haifeng, LI Qiong, SONG Hongzhou, ZHANG Gongmu CHINESE JOURNAL OF COMPUTATIONAL PHYSICS    2019, 36 (4): 379-385.   DOI: 10.19596/j.cnki.1001-246x.7855 Abstract （381）   HTML （83）    PDF （2461KB）（1597）       Knowledge map    We computed equations of state of hydrogen in warm dense matter regime by using DPIMC method. In large part of the regime, pressure difference between DPIMC and RPIMC is less than 10%. In low temperature regime, some difference beyond 20%. We pointed out two clerical errors in pressure of RPIMC. In dissociation and ionization regime, pressures of DPIMC lie between results of TF and TFC model. In dissociation regime, the largest pressure difference between DPIMC and RPIMC is 15%. In ionization regime, pressures of DPIMC are agree with RPIMC. In low density regime, internal energies of DPIMC are close to those of RPIMC, less than those of QMD and those of IG model. In high density regime, pressures of DPIMC lie between results of TFC and IG model, internal energies of DPIMC less than those of IG model. Reference | Related Articles | Metrics