Local hybrid exchange-correlation functionals based on the dimensionless density gradient

A new type of local hybrid functionals with position-dependent admixture of local and exact exchange has been constructed. Different forms, all based on the dimensionless density gradient, are suggested for the local mixing function (LMF), that governs the position dependence. Each of the new LMFs contains one parameter optimized for the atomization energies of the G2-1 set. Performance of several local hybrid functionals has been compared for the thermochemical data of the full G2 set. Only local and exact exchange are mixed in these functionals, without utilizing the generalized gradient approximation. Thermochemical performance for the new local hybrid functionals is competitive with current state-of-the-art hybrid functionals, while the correct asymptotic behavior of the corresponding exchange-correlation potential at long range is satisfied. (C) 2007 Elsevier B.V. All rights reserved.