Experimental observation of open structures in elemental magnesium at terapascal pressures by Gorman, MG, Elatresh, S, Lazicki, A, Cormier, MME, Bonev, SA, McGonegle, D, Briggs, R, Coleman, AL, Rothman, SD, Peacock, L, Bernier, JV, Coppari, F, Braun, DG, Rygg, JR, Fratanduono, DE, Hoffmann, R, Collins, GW, Wark, JS, Smith, RF, Eggert, JH, McMahon, MI