Computational Screening of Dual-Cation Metal Ammine Borohydrides by Density Functional Theory

Abstract

A computational screening study consisting of crystal structure prediction and density functional theory has been performed for dual-cation ammine metal borohydrides (AMBs) with a general formula of M1M2(BH4)3(NH3)2–6 (M1 = Li, Na, or K and M2 = Sr, Ca, Mg, Zn, Mn, or Ni). The stability and decomposition energies of the resulting 90 alloys were used for the evaluation of the screening. It has been observed that two recently synthesized dual-cation AMBs (LiMg(BH4)3(NH3)2 and NaZn(BH4)3(NH3)2) are predicted to form stable alloys. Moreover, the M1(Mn,Mg)(BH4)3(NH3)2–6 and M1Ni(BH4)3(NH3)4–6 alloys, which are not synthesized yet, are also found to be promising.