Benchmarking the Multi-Megabar Phase Diagram of MgO*

Multi-megabar (Mbar) phase transitions of MgO are essential for planetary and high-pressure research but have remained formidable for both theory and experiment (as an example, previously reported[1,2,3] B1–B2 transition pressures vary by ~20%). In this presentation, we show our latest research from first-principles calculations based on density functional theory using an optimal exchange-correlation functional,[4] quantum Monte Carlo,[5] and quantum molecular dynamics.[6] By accurately taking the cold curve and ion and electron thermal contributions into account, our data provide a theoretical benchmark for the multi-Mbar phase diagram of MgO.

[1] J. Bouchet et al., Phys. Rev. B 99, 094113 (2019).
[2] N. Dubrovinskaia et al., https://arxiv.org/abs/1904.00476 (2019).
[3] F. Coppari et al., Nat. Geosci. 6, 926 (2013).
[4] S. Zhang et al., Bull. Am. Phys. Soc. 64, BAPS.2019.MAR.P17.00003 (2019).
[5] S. Zhang et al., Bull. Am. Phys. Soc. 65, BAPS.2020.MAR.M03.00002 (2020).
[6] R. Paul et al., Phys. Rev. Lett. 122, 125701 (2019).