To use the dynamic system model with measured data for candidate materials, parameterized thermodynamic models were fit using the Purdue Metal Hydride Toolbox which was made available at . The process and figures showing comparisons of each model to the measured data can be found in the SI. Four high performing materials investigated in previous work were chosen for low pressure (LP) and medium pressure (MP) stages: A1=Ti 0.955 Zr 0.045 V 0.43 Fe 0.12 Al 0.03 Mn 1.52 (known as Hydralloy C5), A2=Ti 0.95 Zr 0.05 Mn 1.55 V 0.45 Fe 0.09 , A3=TiCrMn 0.7 Fe 0.2 V 0.1 , A4=Ti 1.1 CrMn). TCMCFL was chosen from the current work as the only viable highpressure (HP) stage candidate. Several combinations of these metal hydrides, selected to best match the low-and high-temperature isotherms for the transitions between LP→MP stages and MP→HP stages, were used to predict the performance of 3-stage and 2-stage compressors as shown in Table . For each design, a limited parameter study (varying source pressure, heating and cooling temperatures, and cycle time) was carried out to determine the best performance in terms of compression ratio, hydrogen flow rate at 875 bar delivery pressure, and energy efficiency (calculated as heat required per mass of hydrogen delivered). The parameters that were varied included source pressure, heating and cooling temperatures, and cycle time. Source pressure was varied between 20 and 30 bar for the 3-stage systems and 90-120 bar for the 2-stage systems, hot and cold loop temperatures were constrained to ranges of 150 to 165 • C and 10 to 20 • C, respectively, and half cycle times between 12 to 18 minutes were considered.