Although the composition is predicted to be capable of forming a solid solution mixture using a gradient boosting classifier that essentially reproduces the Hume-Rothery rules, our experimental efforts to synthesize a pure BCC or FCC HEA phase were not successful. However, many other interesting materials lying along the Pareto front can and should be tested in future studies. MgTiCrMnFe, for example, contains no high raw metal costs and has relatively low predicted ∆H = 30 kJ/molH 2 with relatively high capacity of H/M = 1 and Hwt.% = 2.1.