S. Ozgan et M. Keskin, A THEORY OF MELTING OF MOLECULAR-CRYSTALS .2. PHASE-DIAGRAMS AND RELATIONS WITH SOLID-STATE TRANSITIONS, Molecular crystals and liquid crystals science and technology. Section A, Molecular crystals and liquid crystals, 270, 1995, pp. 135-146
The Pople and Karasz theory of melting of molecular crystals is extend
ed to include the third energy parameter mentioned in our previous pap
er.(1) The modified form of the Pople and Karasz theory is used to stu
dy solid-solid transitions and to obtain complete phase diagrams for t
ransitions under pressure. It is found that solid-solid and melting tr
ansitions become second-order under certain conditions. The entropy of
melting as a function of the ratio of the solid transition to boiling
temperature, the theoretical phase diagrams as well as the melting en
tropy versus the solid transition entropy are compared with available
experimental data and as well as the Pople and Karasz theory.