在实验上对非晶材料进行原子尺度研究的手段十分有限,通过模拟的方法可以弥补实验的不足,介绍了一种利用第一性原理对四面体非晶碳进行结构建模的方法。采用基于密度泛函理论的分子动力学方法,对密度范围从2.6~3.2g/cm^3的四面非晶碳进行了结构模拟。其中交换相关能量泛函、假想电子质量和冷却速度等模拟参数对结构建模有较大的影响。通过改变这些模拟参数可以获得与实验值接近的结构。
There are seldom methods to investigate the amorphous materials in atomic-scale,which can be solved through simulation method.A first-principles method to model tetrahedral amorphous carbon was presented.The microstructures of tetrahedral amorphous carbon at densities from 2.6 to 3.2g/cm^3 were simulated using molecular dynamics within the framework of density-functional theory.Exchange-correlation functional,fictitious electronic mass,and cooling rate have great influences.More accurate structures can be obtained by adjusting simulation parameters.