Liquid carbon: structure near the freezing line

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 similar to 300 GPa, the local structure of the liquid along the melting line changes dominant coordination from three- to fourfold.