非晶态碳的结构:碳链的存在
Structure of Amorphous Carbon:Existence of Chain Sites
Abstract
【中文摘要】 对非晶碳的结构在某此低密度下是否有二度配位(sp.链状结构)的存在目前仍然存在争议,在用两种都相当精确的理论方法(Car-Parrinello和紧束缚的分子动力学方法)研究密度约为2g/cm ̄3的非晶碳结构时,对是否有碳链的存在给出完全不同的结论,本文利用第一原理的自治赝势平面波方法,计算了一维sp碳链,二维sP ̄2石墨和三维sp ̄3金刚石结构的结合能、键长等性质随平面波数目的变化,澄清了两个理论结果的矛盾,支持了非晶碳在密度约为2g/cm ̄3时应有碳链存在的结论.
【英文摘要】 The ration of threehold sp ̄2 to fourfold sp ̄3sites and the existence of sp carbonchain in a-Cat some lower density are still subject to controversy. Two well-established theoreti-cal calculations(with Car-Parrinello and Tight-binding molecular dynamics methods)give differ-ent conclusions concerning the existence of carbpon chain in a-C for density around 2 g/cm ̄3.Inorder to resolve the controversies between two theories,we ernploy the norm-conserving non-lo-cal pseudopotential plane wave method to study th...