论文标题
迈向准确的无轨道模拟：非相互作用的自由能密度功能的广义梯度近似
Towards accurate orbital-free simulations: a generalized gradient approximation for the non-interacting free energy density functional
论文作者
论文摘要
对于无轨道{\ it i nibio}分子动力学，尤其是在极端热力学条件下的系统上，我们为非相互作用的自由能提供了第一个伪电位适应的广义梯度近似（GGA）功能。这是通过我们最近的LKT基态非相互作用动能GGA功能的系统有限温度扩展来实现的（Phys。Rev.B \ TextBf {98}，041111（R）（R）（2018））。我们首先通过晶格铝和硅的静态晶格计算来测试新功能的性能。然后，我们将状态结果的氘方程与路径综合蒙特卡洛和常规（轨道依赖性）Kohn-Sham结果进行比较。新功能（表示为LKTF）优于先前最佳的半本地自由能功能，VT84F（Phys。\ Rev. \ b \ b \ textbf {88}，161108（r）（2013）），并提供适度的更快的模拟。我们还讨论了通过从基态无轨道动力学功能扩展获得的动力学和熵贡献对非相互作用的自由能功能的微妙微妙。
For orbital-free {\it ab initio} molecular dynamics, especially on systems in extreme thermodynamic conditions, we provide the first pseudo-potential-adapted generalized gradient approximation (GGA) functional for the non-interacting free energy. This is achieved by systematic finite-temperature extension of our recent LKT ground state non-interacting kinetic energy GGA functional (Phys. Rev. B \textbf{98}, 041111(R) (2018)). We test the performance of the new functional first via static lattice calculations on crystalline aluminum and silicon. Then we compare deuterium equation of state results against both path-integral Monte Carlo and conventional (orbital-dependent) Kohn-Sham results. The new functional, denoted LKTF, outperforms the previous best semi-local free energy functional, VT84F (Phys.\ Rev.\ B \textbf{88}, 161108(R) (2013)), and provides modestly faster simulations. We also discuss subtleties of identification of kinetic and entropic contributions to non-interacting free-energy functionals obtained by extension from ground state orbital-free kinetic energy functionals.
