Conserving controversies of melting line of graphite and graphene

Investigation of melting line of graphite and liquid carbon has long history. However, up to now there are still numerous controversies in the field, for instance, the melting temperatures obtained in different experiments are in very bad agrement. In the present paper we compare several models of carbon widely used in computational studies and the results of ab-initio simulations of liquid carbon. We show that the empirical models fail to reproduce the properties of liquid carbon correctly. We also discuss the “melting” of graphene.