Simulation of delocalized exchange by local density functionals

Exchange holes in molecules can be delocalized over several centers, thus throwing into question their approximation by local density functionals. This work introduces a simple model which detects delocalization in molecules through a local variable related to kinetic energy density. A local exchange functional is derived that reproduces exact-exchange atomization energies of molecules with relatively low error. This has important implications for the simplification of “hybrid” density-functional theories which contain an exactly computed exchange term.

[1]  Parr,et al.  Development of the Colle-Salvetti correlation-energy formula into a functional of the electron density. , 1988, Physical review. B, Condensed matter.

[2]  A. Becke Thermochemical tests of a kinetic-energy dependent exchange-correlation approximation , 1994 .

[3]  Axel D. Becke,et al.  A new inhomogeneity parameter in density-functional theory , 1998 .

[4]  J. Baker,et al.  A study of some organic reactions using density functional theory , 1995 .

[5]  A. Becke,et al.  Exchange holes in inhomogeneous systems: A coordinate-space model. , 1989, Physical review. A, General physics.

[6]  J. C. Slater A Simplification of the Hartree-Fock Method , 1951 .

[7]  Krishnan Raghavachari,et al.  Gaussian-2 theory for molecular energies of first- and second-row compounds , 1991 .

[8]  A. Becke Density-functional thermochemistry. III. The role of exact exchange , 1993 .

[9]  John C. Slater,et al.  The self-consistent field for molecules and solids , 1974 .

[10]  A. Becke Correlation energy of an inhomogeneous electron gas: A coordinate‐space model , 1988 .

[11]  Weitao Yang,et al.  A challenge for density functionals: Self-interaction error increases for systems with a noninteger number of electrons , 1998 .

[12]  A. Becke A New Mixing of Hartree-Fock and Local Density-Functional Theories , 1993 .

[13]  Gustavo E. Scuseria,et al.  Kinetic energy density dependent approximations to the exchange energy , 1999 .

[14]  John P. Perdew,et al.  Exchange-correlation energy of a metallic surface: Wave-vector analysis , 1977 .

[15]  A. Becke,et al.  Density-functional exchange-energy approximation with correct asymptotic behavior. , 1988, Physical review. A, General physics.

[16]  Kieron Burke,et al.  Nonlocality of the density functional for exchange and correlation: Physical origins and chemical consequences , 1998 .

[17]  A. Becke Current-density dependent exchange- correlation functionals , 1996 .

[18]  Axel D. Becke,et al.  Density functionals from the extended G2 test set: Second-order gradient corrections , 1998 .

[19]  Gustavo E. Scuseria,et al.  A novel form for the exchange-correlation energy functional , 1998 .

[20]  J. Perdew,et al.  Accurate and simple density functional for the electronic exchange energy: Generalized gradient approximation. , 1986, Physical review. B, Condensed matter.

[21]  Benny G. Johnson,et al.  An investigation of the performance of a hybrid of Hartree‐Fock and density functional theory , 1992 .