title: Extended Hückel tight-binding approach to electronic excitations.
abstract: In this work, we propose the application of a self-consistent extended Huckel tight-binding (EHTB) method in the computation of the absorption optical spectrum of molecules within the linear response time dependent density functional formalism. The EHTB approach is presented as an approximation to the Kohn-Sham energy functional. The method is applied to the computation of excitation energies and oscillator strengths of benzene, pyridine, naphthalene, diazines, and the fullerenes: C(60)(I(h)), C(70)(D(5h)), and C(80)(D(2)). The very good agreement with experimental data is very encouraging and suggests the possibility of using the EHTB as a computational efficient and reliable tool to study optical properties of a wide variety of molecular systems.
authors.affiliation: NIST Center for Theoretical and Computational Nanosciences, National Institute of Standards and Technology, 100 Bureau Drive, Stop 8380, Gaithersburg, Maryland 20899, USA. lrincon@nist.gov
authors.forename: Luis
authors.initials: L
authors.lastname: Rincón
authors.forename: Anwar
authors.initials: A
authors.lastname: Hasmy
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Gonzalez
authors.forename: Rafael
authors.initials: R
authors.lastname: Almeida
mesh_terms: D000042:Absorption; D004583:Electrons; D037741:Fullerenes / Q000737:chemistry; D009930:Organic Chemicals / Q000737:chemistry; D011789:Quantum Theory; D013997:Time Factors
chemical_list: D037741:Fullerenes; D009930:Organic Chemicals