We apply the long-range correction (LC) scheme for exchange functionals of density functional theory to time-dependent density functional theory (TDDFT) and examine its efficiency in dealing with the serious problems of TDDFT, i.e., the underestimations of Rydberg excitation energies, oscillator strengths, and charge-transfer excitation energies. By calculating vertical excitation energies of typical molecules, it was found that LC-TDDFT gives accurate excitation energies, within an error of 0.5 eV, and reasonable oscillator strengths, while TDDFT employing a pure functional provides 1.5 eV lower excitation energies and two orders of magnitude lower oscillator strengths for the Rydberg excitations. It was also found that LC-TDDFT clearly reproduces the correct asymptotic behavior of the charge-transfer excitation energy of ethylene-tetrafluoroethylene dimer for the long intramolecular distance, unlike a conventional far-nucleus asymptotic correction scheme. It is, therefore, presumed that poor TDDFT results for pure functionals may be due to their lack of a long-range orbital-orbital interaction.

A long-range-corrected time-dependent density functional theory

The nature of the bonding in transition-metal compounds.

Computational methods for the one-particle green's function

Modern aspects of the Jahn-Teller effect theory and applications to molecular problems.

http://casey.brown.edu/chemistry/research/LSWang/publications/239.pdf

All-Boron Aromatic Clusters as Potential New Inorganic Ligands and Building Blocks in Chemistry

30.4-nm He (II) photoelectron spectra of organic molecules: Part VII. Miscellaneous compounds☆

30.4 nm He (II) photoelectron spectra of organic molecules Part VI. Halogeno-compounds (C, H, X; X = Cl, Br, I)☆

The principles of an efficient, fast algorithm for the calculation of diagrams appearing in Green function and many-body perturbation methods are discussed and timing examples are given. Within the suggested algorithm, the third order-diagrams required in the Green function approach are evaluated by arranging computations in such a way that the most inner loops contain only simple scalar products and multiplication of vector by scalar operations. The molecular symmetry is taken into account for abelian groups. © 1993 John Wiley & Sons, Inc.

Vectorizable algorithm for Green function and many-body perturbation methods

30.4-nm He (II) photoelectron spectra of organic molecules: Part III. Oxo-compounds (C, H, O)☆

In this paper we present the optical properties of various structural models for $a\ensuremath{-}\mathrm{Si}$ and $a\ensuremath{-}\mathrm{S}\mathrm{i}:\mathrm{H}.$ We discuss how topological disorder, hydrogen content, and different types of defects (dangling bonds and floating bonds) influence the shape of the optical-absorption spectrum and the position of the Urbach edge. The absorption behavior is characterized by the joint density of states. The band gaps are obtained via the Tauc plot. The principal structure of the optical absorption spectrum is determined mainly by the degree of topological disorder and the amount of hydrogen. The presence of defects gives rise to tail absorption. Dangling bonds affect the optical properties more than floating bonds do.

Wolfgang von Niessen

Papers

30.4-nm He (II) photoelectron spectra of organic molecules: Part VII. Miscellaneous compounds☆

30.4 nm He (II) photoelectron spectra of organic molecules Part VI. Halogeno-compounds (C, H, X; X = Cl, Br, I)☆

Vectorizable algorithm for Green function and many-body perturbation methods

30.4-nm He (II) photoelectron spectra of organic molecules: Part III. Oxo-compounds (C, H, O)☆

Disorder, defects, and optical absorption in a-si and a-si:h