Formulae for the first and second derivatives of anisotropie potentials with respect to geometrical parameters

We have derived formulae for the forces and torques arising from the electrostatic energy of a system of rigid molecules, using a rigorous unified approach. We have also obtained systematically the second derivatives with respect to transla-tional and rotational coordinates. Some of the properties of first and second derivatives are discussed for the general case of a system with arbitrary symmetry. Derivatives of a general anisotropic exponential repulsive potential have also been evaluated. All of these have been implemented as Fortran subroutines in the Orient program.