高压下BaN2晶体结构的物理性质

基于第一性原理的卡里普索(CALYPSO)晶体结构预测方法,在0～100 GPa压力下研究了BaN₂晶体的相变行为及其物理性质.研究发现:在常压下BaN₂晶体为α -BaN₂相结构,其空间群为C2/c; 压力为31 GPa时,晶体结构由α -BaN₂相转变为β -BaN₂相,其空间群为P2₁/c.计算α -BaN₂相和β -BaN₂相的能带结构显示, α -BaN₂相具有金属特征, β -BaN₂相具有半导体性质.计算Bader电荷转移显示,电荷从Ba原子向N原子转移,其中N原子是受主, Ba原子是施主.

Physical properties of BaN2 crystal structure under high pressure

Based on the first -principle CALYPSO crystal structure prediction method, the phase transition behavior and physical properties of BaN₂ crystals were studied at a pressure of 0 -100 GPa. The study found that BaN₂ crystals have an α -BaN₂ phase structure with a space group of C2/c under normal pressure; when the pressure is 31 GPa, the crystal structure changes from α -BaN₂ phase to β -BaN₂ phase with a space group of P2₁/c. Calculation of the energy band structure of α -BaN₂ phase and β -BaN₂ phase shows that α -BaN₂ phase has metallic characteristics and β -BaN₂ phase has semiconductor properties. Calculating Bader charge transfer shows that the charge transfer from B a atom to N atom, where N atom is the acceptor and B a atom is the donor.