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. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3247288]