LS220nl (no low densities)
This table contains the EoS by Lattimer and Swesty [LSNP_1991] with compression modulus K = 220 MeV. The nuclear interaction is an effective non-relativistic Skyrme type model without momentum dependence. Within the inhomogeneous phase at low density, nuclei are supposed to arrange themselves in a body centered cubic lattice which maximizes the separation of ions. According to the Wigner-Seitz approximation, each ion is at the center of a neutral-charged cell, surrounded by a gas of free nucleons, α-particles and electrons. Interactions between the outside gas and the nuclei are taken into account through an excluded volume. Nucleons are treated as non-relativistic particles; α-particles as hard spheres of volume v α = 24 fm 3 forming an ideal Boltzmann gas. As the density increases, nuclei undergo geometrical shape deformations, until they dissolve in favor of homogeneous nuclear matter above approximately saturation density. The formation of non-spherical nuclei is described by modifying the Coulomb and surface energies of nuclei, as discussed in Section 2.8 of Ref. [LSNP_1991]. The transition to bulk nuclear matter is treated by a Maxwell construction. The configuration of matter and the balance between the different phases is given by the thermodynamically most favorable state, i.e. the one which minimizes the Helmholtz free energy of the system. This procedure, minimizing the free energy, guarantees that the LS EOS is thermodynamically consistent. Further details can be found in Ref. [LSNP_1991]. The web page www.astro.sunysb.edu/dswesty/lseos.htm contains additional information as well as the original code for downloading.