Theoretical Prediction of Crystal Structure of Mo₂Ga₂B and Its Evolution to Layered Boride Mo₂B

Conventional M n +1 AX n phases are a large family of compounds that have been limited to carbides and nitrides. Herein, the stable structure of Mo 2 Ga 2 B, a typical boron‐based ternary phase in the Mo‐Ga‐B system, using a computational structure search approach is predicted. The predicted hexagonal‐layered structure is the typical structure of traditional M n +1 AX n phases, and two Ga layers separate Mo 2 B blocks in Mo 2 Ga 2 B, which is different from the M 2 AX phases. The analysis of phonon dispersions and elastic constants confirms that the hexagonal‐layered structure exhibits both dynamical and mechanical stability, respectively. The tensile and shear stress–strain curves are obtained, and the structural stability is investigated by analyzing the stability of chemical bonds under tensile and shear deformations. Layered Mo 2 B can be obtained by the removal of Ga layer from the precursor Mo 2 Ga 2 B. Theoretical predictions indicate that monolayer Mo 2 B is metallic, and has potential applications as an anode and thermoelectric material.