The Comment of Pace et al. [Phys. Rev. B 98, 106101 (2018)] claims that structural analysis and nomenclature of Zhang et al. [Zhang, Xu, Wang, Jiang, Gorelli, Greenberg, Prakapenka, and Goncharov, Phys. Rev. B 97, 064107 (2018)] are incorrect, that this compound is not metallic at high pressures and 200 K, and that the compound instead decomposes. In this Reply we argue that there are no experimental data that can discriminate between theoretically predicted Cccm ${\mathrm{H}}_3\mathrm{Se}$ and $I$4/mcm ${\left({\mathrm{H}}_2\mathrm{Se}\right)}_2{\mathrm{H}}_2$ advocated by Pace et al. The difference in nomenclature is due to different naming conventions. We find the name “${\mathrm{H}}_3\mathrm{Se}$” more convenient to apply in the limit of high pressure. We also substantiate the initial claims of the stability up to 40 GPa at 170 K of the ${\mathrm{H}}_3\mathrm{Se}$ compound after synthesis at 4.6 GPa and argue that the pressure induced metallization above 23 GPa is a plausible explanation of the reported visual observations and Raman spectroscopy results.

• Received 19 June 2018
• Revised 8 August 2018

DOI:https://doi.org/10.1103/PhysRevB.98.106102