Local isoelectronic reactivity of solid surfaces

The quantity w^N(r) = (1/ k^2 T_el)[partial n(r, T_el) / partial T_el]_(v(r), N) is introduced as a convenient measure of the local isoelectronic reactivity of surfaces. It characterizes the local polarizability of the surface and it can be calculated easily. The quantity w^N(r) supplements the charge transfer reactivity measured e.g. by the local softness to which it is closely related. We demonstrate the applicability and virtues of the function w^N(r) for the example of hydrogen dissociation and adsorption on Pd(100).