中文摘要：

基于密度泛函理论，采用了一种更为精确的交换相关泛函OLYP（OPT）（＋LYP），对密度范围从2.0到3.2g/cm^3的非晶碳进行结构建模。模拟得到的5个碳网络结构无论从径向分布函数还是sp^3含量都与实验符合得很好,对非晶碳电子结构的研究表明费米能级附近的电子态密度主要是sp^2碳原子的贡献。随着密度的增加，sp^3碳原子增加，费米能级附近的态密度越来越小,小环结构增加了费米能级附近的电子态密度，缺陷态在费米能级形成尖峰，使带隙大大降低。

英文摘要：

Within the framework of density-functional theory, a new and more accurate exchange correlation functional OLYP（OPTX ＋ LYP） was used to simulate the structures of amorphous carbon at densities from 2.0 to 3.2 g/cm^3 . The radial distribution function and sp^3 fraction of the five simulated carbon networks are in good agreement with experimental results. The calculated electronic structures indicate that the states near Fermi level are mainly contributed by sp^2 carbon atoms. The states near Fermi level have a decreasing trend with increasing density and increasing sp^3 content. The small ring structure increases the density of states near Fermi level. The defects will give a peak at Fermi level, which strongly reduces the band gap.