LAUSR

Abstract To assess the performance of our implemented first principles isothermal-isobaric centroid molecular dynamics (CMD) we performed Born-Oppenheimer (BO) CMD simulations in the NPT ensemble for high pressure ices (HPIs) VIII, VII, and X at 270 K. By elevating pressure the crystal system is found to transform from tetragonal to cubic at ∼ 30 GPa, accompanying the proton order (ice VIII)-disorder (ice VII) transition observed to occur in our BO-CMD simulations. Moreover, our simulations are proved to be able to reproduce well both infrared and Raman spectra for HPIs in the frequency range above ∼ 500  cm −1 .