Anticipating Pressure Changes in Halides under Compression

A new equation of state (NEOS) for Halides has been developed using the theory of lattice potential and the concept of volume dependence of the short-range force constant. The derivation of this equation of state involved the use of the third-order approximation of the lattice potential. A comparative analysis was conducted between the isothermal equations of state, including Vinet EOS, Murnaghan EOS, Holzapfel EOS, Born-Mie EOS, Birch-Murnaghan EOS, and the newly derived NEOS. The NEOS was used to analyze the compression behavior of Halides, and it was found that Vinet EOS and NEOS agreed with the experimental data for Halides up to high compression. However, Murnaghan EOS, Born-Mie EOS, Holzapfel EOS, and Birch-Murnaghan EOS are usually less sensitive to calculating pressure at high compression. It was also observed that for some Halides, such as NaBr and NaI, Vinet EOS could not produce results consistent with experimental findings. In contrast, NEOS consistently produced results that matched the experimental findings for all Halides samples, unequivocally demonstrating its reliability and accuracy.