Equations of state of poly-α-methylstyrene and polystyrene: First-principles calculations versus precision measurements

We show with a recently devised extended first-principles molecular dynamics method that calculated Hugoniots of poly-a-methylstyrene agree well with precision experimental results of Kritcher et al. [Nature (London) 584, 51 (2020)] and Doppner et al. [Phys. Rev. Lett. 121, 025001 (2018)]. The deviation is smaller than 0.8%. This agreement does not sensitively rely on the approximations in the employed first-principles methods as long as underlying physics are well described, as illustrated in the calculation of equation of state for polystyrene covering the warm dense regime. These results may stimulate a broad range of quantitative investigations on warm dense matter that were not thought possible before, and may thus afford a new prospect to the field of inertial confinement fusion and high-energy-density physics.

Automated summary

The newly developed extended first-principles molecular dynamics method accurately predicts the Hugoniots of poly-a-methylstyrene, showing good agreement with experimental results. This opens up possibilities for further quantitative studies on warm dense matter.