苯甲酸单晶的制备及晶体结构、能带结构和光学性质的第一性原理计算

合成了化合物苯甲酸(C6H5COOH),并通过X射线单晶衍射对其结构进行了测定。该化合物属于三斜晶系,P1-空间群,晶胞参数为a=0.515 6(8)nm,b=0.552 1(8)nm,c=2.204 9(3)nm,α=97.19°,V=0.622 8(16)nm3,Z=18。采用基于密度泛函理论的第一性原理平面波赝势方法的CASTEP计算模块研究了苯甲酸晶体的基态性质,包括几何优化后的态密度、能带结构和基本的光学函数。利用精确计算的能带结构和态密度,分析了苯甲酸单晶材料的反射谱、吸收谱和介电函数,为苯甲酸单晶材料在光、电领域的应用提供了理论依据。

Synthesis,Crystal Structure,First-principle Calculation on Band Structures and Optical Properties of Benzoic Acid

The crystal of benzoic acid(C7H6O2) has been prepared and structurally determined by X-ray single-crystal diffraction.The titled compound crystallized in the triclinic system,space group P1-with a = 0.515 6(8) nm,b=0.552 1(8) nm,c=2.204 9(3) nm,α= 97.19°,V =0.622 8(16) nm3,Z=18.The first-principle calculations were performed with CASTEP code in MS modeling based on the plane wave basis set.The properties of static state,including band structures,densities of states(DOS) and optical properties,were calculated by the CASTEP method,which based on the density functional theory(DFT) using a plane-wave expansion of the wave functions.The dielectric constant,the absorption and reflectivity spectra were analyzed according to the calculated band structure and the density of states(DOS).The calculated results were in well agreement with the experiment value.