  We examine the model dependence of the phase diagram of inhomogeneous nulcear
matter in supernova cores using the quantum molecular dynamics (QMD).
Inhomogeneous matter includes crystallized matter with nonspherical nuclei -
"pasta" phases - and the liquid-gas phase separating nuclear matter. Major
differences between the phase diagrams of the QMD models can be explained by
the energy of pure neutron matter at low densities and the saturation density
of asymmetric nuclear matter. We show the density dependence of the symmetry
energy is also useful to understand uncertainties of the phase diagram. We
point out that, for typical nuclear models, the mass fraction of the pasta
phases in the later stage of the collapsing cores is higher than 10-20 %.
