Please use this identifier to cite or link to this item:
Title: Benchmark theoretical study of the ionization threshold of benzene and oligoacenes
Authors: DELEUZE, Michael 
FRANCOIS, Jean-Pierre
Issue Date: 2003
Source: JOURNAL OF CHEMICAL PHYSICS, 119(6). p. 3106-3119
Abstract: In straightforward continuation of Green's function studies of the ultraviolet photoelectron spectra of polycyclic aromatic compounds [Deleuze , J. Chem. Phys. 115, 5859 (2001); M. S. Deleuze, ibid. 116, 7012 (2002)], we present a benchmark theoretical determination of the ionization thresholds of benzene, naphthalene, anthracene, naphthacene (tetracene), pentacene, and hexacene, within chemical accuracy [0.02-0.07 eV]. The vertical ionization potentials of these compounds have been obtained from series of single-point calculations at the Hartree-Fock, second-, third-, and partial fourth-order Moller-Plesset (MP2, MP3, MP4SDQ) levels, and from coupled cluster calculations including single and double excitations (CCSD) as well as a perturbative estimate of connected triple excitations [CCSD(T)], using basis sets of improving quality, introducing up to 510, 790, 1070, 1350, 1630, and 1910 basis functions in the computations, respectively. A focal point analysis of the convergence of the calculated ionization potentials has been performed in order to extrapolate the CCSD(T) results to an asymptotically (cc-pVinfinityZ) complete basis set. The present results confirm the adequacy of the outer-valence Green's function scheme for strongly correlated systems. Adiabatic ionization energies have been further determined by incorporating Beck-three-parameter Lee-Yang-Parr functional corrections for zero-point vibrational energies and for geometrical relaxations. Extension of the analysis to the CCSD(T)/cc-pVinfinityZ level shows that the energy minimum form of the benzene radical cation is an obtuse structure related to the B-2(2g) state. Isotopic shifts of the adiabatic ionization potentials, due to deuterium substitution of hydrogens, have also been discussed. (C) 2003 American Institute of Physics.
Notes: Limburgs Univ Centrum, Dept SBG, B-3590 Diepenbeek, Belgium. Bogoliubov Inst Theoret Phys, UA-03143 Kiev 143, Ukraine.Deleuze, MS, Limburgs Univ Centrum, Dept SBG, Univ Campus, B-3590 Diepenbeek, Belgium.
Document URI:
ISSN: 0021-9606
e-ISSN: 1089-7690
DOI: 10.1063/1.1589731
ISI #: 000184350300019
Category: A1
Type: Journal Contribution
Validations: ecoom 2004
Appears in Collections:Research publications

Show full item record


checked on Sep 3, 2020


checked on May 22, 2022

Page view(s)

checked on May 25, 2022

Google ScholarTM



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.