In the same way as in our previous work [2], the total intermolecular potential energy Ut was computed as the sum of non-electrostatic and electrostatic contributions. The non-electrostatic contribution (ULJ) was computed by use of the LJ pair potential model and the electrostatic contribution (UCoul) was computed by means of the Ewald summation method [42], [43], [44], [45] and [46] for the Coulombic potential, as follows: