Supplementary Online Material

Snapshots of all ions for the α and β phases, potential parameters for the cation and anion of the IL, gCRC1 and gPF for bulk IL, α, and β phases, CV1 and CV2 as a function of time at four different periods, snapshots of ions for phases emerged in the MTD simulation starting with a different initial configuration, FES created using the simulation data for different periods of the run, FES created with the MTD simulation using the well-tempered method, snapshots of all ions projected onto the xy and xz planes for phase B, distributions of the angle formed by three nearest neighbor P atoms for phases B and C, snapshots of ions for a phase emerged in the MTD simulation for the α system, snapshots of ions for a typical high-density phase appeared in the MTD simulation with gPP as CV2