Figure S13 shows the pressure dependence of the fractions of O(j) (j = I, II, III or IV) species for (a) glassy CaAS_25_50 at 27 Celsius, (b) liquid CaAS_25_50 at 2,227 Celsius, and (c) glassy CaAS_19_61 and CaAS_26_49 at 25 Celsius.