Journal of Physical Chemistry, Vol.99, No.23, 9337-9339, 1995
Chemical Hardness in Density-Functional Theory
Variations of the chemical hardness and other global molecular quantities are considered in "pure-state" density functional theory. It is found from symmetry considerations that the hardness is an extremum with respect to symmetry breaking variations about a symmetric configuration of the nuclei. The relation of this result to the principle of maximum hardness is discussed.