title: Electronic responses of long chains to electrostatic fields: Hartree-Fock vs. density-functional theory: a model study.
abstract: The response to an electrostatic field is determined through simple model calculations, within both the restricted Hartree-Fock and density functional theory methods, for long, finite as well as infinite, periodic chains. The permanent dipole moment, μ0, the polarizability, α, and the hyperpolarizabilities β and γ, calculated using a finite-field approach, are extensively analyzed. Our simple model allows for treatment of large systems and for separation of the properties into atomic and unit-cell contributions. That part of the response properties attributable to the terminations of the finite system change into delocalized current contributions in the corresponding infinite periodic system. Special emphasis is placed on analyzing the reasons behind the dramatic overestimation of the response properties found with density functional theory methods presently in common use.
authors: Physical and Theoretical Chemistry, University of Saarland, 66123 Saarbrücken, Germany.
authors: Jorge
authors: J
authors: Vargas
authors: Physical and Theoretical Chemistry, University of Saarland, 66123 Saarbrücken, Germany.
authors: Michael
authors: M
authors: Springborg
authors: Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, USA.
authors: Bernard
authors: B
authors: Kirtman