VARIATIONAL CALCULATION OF THE GLOBAL HARDNESS AND THE FUKUI FUNCTIONVIA AN APPROXIMATION OF THE HARDNESS KERNEL

An implementation of the variational principle for the chemical hardne ss [P. K. Chattaraj, A. Cedillo and R.G. Parr, J. Chem. Phys., 103, 76 45(1995)] is described, which uses a simple approximation to the hardn ess kernel. The molecular Fukui function is taken to be a linear combi nation of atomic Fukui functions, which are expanded in a set of Gauss ian type orbitals. This methodology is shown to yield results which ar e largely in agreement with sensitivity analysis methods of Mortier, N alewajski, and coworkers.