“…The structure searches for Rb x Mg y H z (x = 1-2, y = 1-2, z = 1-4, 6, 8-10, 12, 16, 18, 24, 28) at 100, 200, and 300 GPa were carried out using a particle-swarm optimization algorithm implemented in the CALYPSO software, [45][46][47] which has been successfully applied to various high-pressure systems. [48][49][50][51][52][53] Simulated cells containing up to 62 atoms were adopted. The total number of searched structures in this work was around 151 000.…”