材料中原子的化学计量比和站位可以显著的影响材料的结构和物理性质，研究具有异常化学计量比的材料在理论和实验上都有极为重要的意义。在极端条件下，压力通过缩小原子间距，可以显著地改变原子键合，从而改变固体材料的物性。高温高压下可以合成常压下无法生成的新化学态和具有特殊物理性质的新物质。在已有工作的基础上，本项目将致力于在金属卤化物、金属氢化物、高密度氮化物和轻元素骨架材料中发现具有新奇化学计量比的化合物。通过理论计算和实验的紧密结合，在各种不同的压力和温度条件下，利用USPEX演化算法来预测高压下化合物的晶体结构，采用激光加热金刚石对顶砧技术来合成新化学态物质。原位的X射线衍射、拉曼光谱和电输运测量将完整的呈现这些新化合物的结构和物性。

Stoichiometry and atomic ordering state are expected to affect critically the structure and physical properties of the materials. It is important that to investigate the materials with unusual stoichiometric ratio both in theory and experiment. Under extreme conditions, the pressurecan significantly change the atomic bonding by compressing the atomic spacing, so as to change the properties of solid materials.Under high temperature and pressure,the materials with novel chemical state and special physical properties can be synthesized. On the basis of the previous works, our research will focus on the metal halide, metal hydride, high density nitrideand and light elements frameworks and is aimed to fabricate the compounds with novel stoichiometric ratio. By combining of the theory and experiment, we will use USPEX evolutionary algorithm to predict the crystal structures of the compounds and synthesize the compounds with novel chemical state by laser heating diamond anvil cells technique.In situ X-ray diffraction, Raman spectra and electrical transport measurements will completely present the structure and physical properties of these new compounds.