Equation of state for solids developed by Born-Mayer, Birch and Poirier- Tarantola have been used here to determine the pressure-volume relationships for LiF, LiCl,and LiBr solids. The results obtained through the Born- Mayer and Birch equation of states are in good agreement with each other but the calculated values obtained from Poirier- Tarantola EOS are different at higher compression ranges. The computed results suggest the validity of Born-Mayer and Birch equation of states for the prediction of pressure-volume relationships for Lithium Halides is good at higher compression ranges but Poirier- Tarantola EOS shows its validity only at low compression range specially upto the compression range (from V/V0=1.0 to 0.77). The validity of these equation of states are due to the consideration of different approximation regarding change in strain due to the compression.
