  The alkali halides have been studied very frequently for their simple
structures and interesting properties, for example, the high-pressure induced
transition$^1$. There are several successful models that can be employed. The
most famous model of them is the Tosi-Fumi interionic potential$^2$ which is an
empirical potential derived from the experimental data. Whereas, here we
developed a new potential model based on the M\"{o}bius lattice inversion
method$^{3,4}$, which can be derived directly from the cohesive energy curve
without any experimental data and is more effective than the ab initial
calculation. With the M\"{o}bius interionic potentials, we calculated the
structural and elastic properties of RbCl crystal. The results are in good
agreement with experiments. We also studied the high-pressure induced B1-B2
transition of RbCl crystal and estimated approximately the transition-point
which is about 1.09GPa. Further more, we used this potential model to simulate
the RbCl melting with molecular dynamics. The calculated melt-point is
approximately 990K$\sim$995K, close to the experimental data.
