Calculation of force constants with the Maximum Overlap Method, II. Molecules with lone pair electrons or empty orbitals Abstract: We have shown that the {\it maximum overlap method} can be used, provided the central atom does not possess any lone pair electrons. The stretching and stretching-bending force constants of BF$_3$ were computed up to a constant factor with our previously applied method. The sign of the non-diagonal force constant was obtained correctly in this case, too.