ANALYTICAL DERIVATIVES OF ATOMIC ZERO-FLUX SURFACES AND PROPERTIES OFATOMS IN MOLECULES WITH RESPECT TO EXTERNAL PERTURBATIONS

A complete theory of the response of the atomic zero-flux surfaces to external perturbations is presented. The resulting expressions for the analytical derivatives of the properties of atoms in molecules (AIMs) are implemented in an efficient computer code. Several test calculati ons demonstrate the clear advantages of the new approach over methods based upon numerical differentiation. The present development opens an avenue to routine calculations of the second-order response propertie s of AIMs. (C) 1996 American Institute of Physics.