Progress in the Development of Advanced Temperature-Dependent Free-Energy Density Functionals Beyond the Generalized Gradient Approximation*

We present our progress in developing free-energy density functionals that include exchange-correlation (XC) thermal effects for improving the accuracy of Kohn-Sham calculations at elevated temperatures (T). The recently developed local-density approximation corrKSDT, generalized-gradient approximation (GGA) KDT16 [1], and hybrid-level KDT0 [2] show that XC thermal effects are significant in certain thermodynamic conditions and that further development of thermal functionals is necessary. Here, we present a finite-T version of the meta-GGA functional SCAN-L (the de-orbitalized version of SCAN [3]) and the popular hybrid functional HSE06. Our results show an improved agreement with experiment in calculations such as Hugoniot and optical properties of materials of interest to planetary science and inertial confinement fusion.

[1] V. V. Karasiev, J. W. Dufty, and S. B. Trickey, Phys. Rev. Lett. 120, 076401 (2018).
[2] D. I. Mihaylov, V. V. Karasiev, and S. X. Hu, Phys. Rev. B 101, 245141 (2020).
[3] D. Mejia-Rodriguez and S. B. Trickey, Phys. Rev. A 96, 052512 (2017).