基于N_(4)分子的高能量密度材料:第一性原理计算的合成路线

High Energy Density Materials based on N_(4) Molecules:Synthesis Routes from First-principles Calculations

为了探索合成和稳定聚合氮形式的分子或晶体的途径,基于第一性原理计算提出了两种基于N_(4)分子合成高能量密度材料的方法:第一种方法是在单晶金属表面吸附N_(4)(T_(d))分子;第二种方法是利用结构搜索获取稳定的N_(4)相关结构。提出了P-43m-N_(4)、P_(4)/m-LiN_(4)和Amm2-G/N_(4)三种含有N_(4)分子的晶体,并计算了它们的能量密度、热力学和动力学稳定性以及电子结构性质。结果表明,在超高真空和低温条件下,N_(4)(T_(d))在金属表面可以通过失去T_(d)对称而稳定。AIMD模拟结果表明,它们在50GPa、50或300K下是稳定的。通过N_(4)与金属原子形成的配位键,聚合N_(4)可以在高压下合成,并在低温条件下稳定。

To explore the routes for synthesizing and stabilizing polymeric nitrogen in molecules or crystals,two methods for synthesizing high energy density materials(HEDM)based on N_(4)molecules were proposed based on the first-principles calculations.The first route is to adsorb N_(4)(T_(d))molecule on single crystal metal surfaces,and the second method is to use structural search to obtain stable N_(4)-related structures.Three N_(4)-containing crystals,P-43m-N_(4),P_(4)/m-LiN_(4)and Amm2-G/N_(4)were proposed,and their energy densities,thermodynamic and kinetic stabilities,as well as their electronic properties were calculated.The results show that under ultra-high vacuum and low temperature conditions,N_(4)(T_(d))can be stabilized by losing the T_(d) symmetry on the metal surfaces.AIMD simulations indicate that they are stable at 50GPa and 50 or 300K.Through coordination bond between N_(4)and metal atoms,polymerized N_(4)can be synthesized at high pressure and stabilized at low temperature conditions.