Local hybrids as a perturbation to global hybrid functionals.

We present new local hybrids of generalized gradient approximation exchange, designed to be small perturbations to the corresponding global hybrid. In general, local hybrids include a position-dependent admixture of nonlocal Hartree-Fock exchange. These new local hybrids incorporate a constant fraction of nonlocal exchange, plus additional nonlocal exchange contributions near nuclei. These functionals predict molecular thermochemistry and reaction barriers on average more accurately than their "parent" global hybrid.