The coexistence line of two high-pressure phases of solid nitrogen: molecular and polymeric cubic gauche
(CG) has been predicted using two separate equations of state. Phase transition parameters: latent heat, volume and entropy jumps were calculated. At low temperature the predicted volume jump ΔV(P) is in agreement with recent experimental data; at elevated temperatures P(T)-curve tends to the vicinity of the pressure maximum on the melting line.
PACS: 05.70.Fh Phase transitions: general studies; PACS: 61.50.Ks Crystallographic aspects of phase transformations; pressure effects; PACS: 64.10.+h General theory of equations of state and phase equilibria.