van de Streek J, Verwer P, Bennema P, Vlieg E

Abstract:
It is known that the experimental triclinic crystal structures of even n-alkanes are not well reproduced upon energy
minimization with current force fields. The inclusion of electrostatics does not solve this, and, moreover, some charge
schemes show unphysical features such as positively charged carbon atoms or charge alternation. The effect of the
electrostatics on the energies of the crystal structures of the even n-alkanes, and thereby on their polymorphism, has
never been established. A new charge scheme is introduced that yields physically sensible charges without constraints.
It will also be shown, however, that electrostatics are relevant neither for the structures of the crystals, nor for their
energies.