title: Density-Functional-Based Determination of Vibrational Polarizabilities in Molecules within the Double-Harmonic Approximation:  Derivation and Application.
abstract: We present a nonperturbative derivation for the primary contribution to the vibrational polarizability for molecules, clusters, and other finite systems. Using a double-harmonic approximation and a finite-field approach the vibrational polarizability is calculated within the generalized gradient approximation to the density functional theory for a variety of molecules and clusters. The agreement between theory and experiment is quite good. The results show that for small ionic molecules and clusters, inclusion of the vibrational polarizability is necessary to achieve agreement with experiment.
authors.affiliation: Center for Computational Materials Science, Code 6390, Naval Research Laboratory, Washington, DC 20375, Department of Electrical and Computer Engineering, Howard University, Washington, DC 20059, and Department of Physics and Astronomy, State University of New York, Stony Brook, New York 11794-3800.
authors.forename: Mark R
authors.initials: MR
authors.lastname: Pederson
authors.affiliation: Center for Computational Materials Science, Code 6390, Naval Research Laboratory, Washington, DC 20375, Department of Electrical and Computer Engineering, Howard University, Washington, DC 20059, and Department of Physics and Astronomy, State University of New York, Stony Brook, New York 11794-3800.
authors.forename: Tunna
authors.initials: T
authors.lastname: Baruah
authors.affiliation: Center for Computational Materials Science, Code 6390, Naval Research Laboratory, Washington, DC 20375, Department of Electrical and Computer Engineering, Howard University, Washington, DC 20059, and Department of Physics and Astronomy, State University of New York, Stony Brook, New York 11794-3800.
authors.forename: Philip B
authors.initials: PB
authors.lastname: Allen
authors.affiliation: Center for Computational Materials Science, Code 6390, Naval Research Laboratory, Washington, DC 20375, Department of Electrical and Computer Engineering, Howard University, Washington, DC 20059, and Department of Physics and Astronomy, State University of New York, Stony Brook, New York 11794-3800.
authors.forename: Christian
authors.initials: C
authors.lastname: Schmidt