Comparison of modified Morse and Rose equations of state for solids

Abstract： The Morse EOS is modified (MM EOS) to consider the Fermi gas limitation, and compared with the modified effective Rydberg (ME) and modified Rose (MR) EOSs in literature. By applying the MM, ME and MR EOSs to 50 materials, it is shown that the MM EOS gives the slightly best results, the ME and MR EOSs give slightly inferior results. However, the physically incorrect oscillations may occur in the pressure and energy curves of the MR EOS for some solids in the high-pressure region. The MR EOS is not suitable for practical applications.