Molecular-dynamics studies on the shock-induced phase transition of aMgF2crystal

The shock-induced phase transition of a MgF2 crystal with the rutile structure was simulated by means of a molecular-dynamics (MD) calculation, where the simplified interatomic potential function was applied. We found that the rutile structure of a MgF2 crystal is transformed to the cubic fluorite structure in several femtoseconds through both the static and the biaxial shock-compression processes of the MD calculation, in which the transition pressure at room temperature was successfully reproduced. Moreover, we revealed explicitly that the mechanism of the rutile-cubic phase transition is mainly due to the rotational motion of F- ions surrounding the Mg2+ ion in the crystal. © 1995 The American Physical Society