Liquid carbon: structure near the freezing line

Abstract

We present a detailed analysis of the structure of liquid carbon near the freezing line. The results are obtained by molecular simulation using a recently developed state-of-the-art bond order potential. We find that along the melting line the liquid is predominantly threefold coordinated up to pressures far beyond the liquid–graphite–diamond triple point. We find no sign of a first-order liquid–liquid phase transition when, at 10 500 K and ~300 GPa, the local structure of the liquid along the melting line changes dominant coordination from three- to fourfold.