高压下晶体5-硝胺基-3,4-二硝基吡唑肼结构转变的周期性密度泛函理论研究

Periodic DFT Study on Structural Transformations of Crystalline Hydrazinium 5-Nitramino-3,4-dinitropyrazolate Under High Pressures

采用周期性密度泛函理论(DFT)方法研究了静水压0~160 GPa范围内5-硝胺基-3,4-二硝基吡唑肼(HNDP)的晶体结构、分子结构和电子结构.研究结果表明,晶体HNDP在静水压6,28和110 GPa时发生了3次结构转变:在6 GPa时,分子中阴离子和阳离子的相对位置发生重排,N17—H23…N13氢键断裂;在28GPa时再次形成N17—H23…N13氢键;在110 GPa时,N17—H19共价键转变为氢键,形成N20—H22…O24共价键.带隙、键布居数以及原子电荷研究结果表明,随着压强增加,晶体HNDP的金属性及离域性增强.

Periodic density functional theory（DFT）calculations were performed to study the crystal,molecular and electronic structures of energetic hydrazinium 5-nitramino-3,4-dinitropyrazolate（HNDP）in the pressure range of 0—160 GPa.The results indicate that crystalline HNDP undergoes three structural transformations.The first one occurs at 6 GPa with the rearrangement of the molecules in the crystal and the rupture of the N17—H23…N13 hydrogen bond.At 28 GPa,the second one forms N17—H23…N13 hydrogen bond again.The last one occurs at 110 GPa with the rupture of the N17—H19 covalent bond and N20—H22…O24hydrogen bond.An analysis of band gaps,bond populations and atomic charges show that HNDP crystal undergoes an electronic transition to the metallic system with the increase in pressure.These results provide basic information for the high pressure behavior of crystalline HNDP.