Surface free energy of the crystal-liquid interface on the metastable extension of the melting curve

The surface free energy $\gamma$, excess surface energy $e$, and excess surface stress $\tau$ at the crystal-liquid interface of a Lennard-Jones system have been determined by molecular dynamics simulation. The calculations have been performed for temperatures both above and below the triple-point temperature for the region where each of the coexisting phases is metastable and is at a negative pressure. The asymptotic behavior of $\gamma$, $e$, and $\tau$ has been analyzed near the endpoint of the melting curve, which is a point of the contact of the metastable extension of the melting curve and the spinodal of the stretched liquid [V.G. Baidakov and S.P. Protsenko, Phys. Rev. Lett. 95, 015701 (2005)]. It has been found that $\gamma$, $e$, and $\tau$ at this point are finite and the excess surface entropy is zero.