Symmetry Conservation in Fukui Functions.

The problem of symmetry breaking in the evaluation of Fukui functions is addressed. It is also demonstrated that a reliable solution of the problem can be achieved using analytic methods. An automatic method that avoids occurrence of symmetry breaks has been implemented in a computer code and is described here. Negative regions of the Fukui function are shown to play a key role for the interpretation of reactivity. Example plots are presented for diatomic molecules, inorganic molecules, conjugated systems, and molecular cages. The potentiality of the Fukui functions as molecular scalar fields for prediction and analysis of regioselectivity is enhanced. Its advantages with respect to the use of condensed Fukui functions are discussed.