First-principles-assisted band gap predictions of methylammonium metal formates

Identifying metal-organic frameworks that are applicable in the visible light area is significant. In this study, the band gaps of six different systems of methylammonium metal formates ([CH3NH3][M(HCOO)(3)] (M = Ni, Cu, Zn, Ge, Sn, and Ba)) were examined systematically. The formation energies of hypothetically designed systems of methylammonium germanium formate ([CH3NH3][Ge(HCOO)(3)]), methylammonium tin formate ([CH3NH3][Sn (HCOO)(3)]), and methylammonium barium formate ([CH3NH3][Ba(HCOO)(3)]) were calculated to investigate their stability. Among the compounds, methylammonium barium formate ([CH3NH3][Ba(HCOO)(3)]) and methylammonium copper formate ([CH3NH3][Cu(HCOO)(3)]) possessed the highest and lowest band gap, respectively. In addition, the effects of charge transfer and pressure on the band gaps of methylammonium nickel formate ([CH3NH3][Ni(HCOO)(3)]) were explored.

Automated summary

This study systematically examined the band gaps of several metal-organic frameworks and calculated their stabilities, revealing that the band gap of methylammonium barium formate was the highest while that of methylammonium copper formate was the lowest. Additionally, the effects of charge transfer and pressure on the band gaps of methylammonium nickel formate were explored.