skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Determination of adiabatic ionization potentials and electron affinities of energetic molecules with the Gaussian-4 method

Authors:
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1413071
Grant/Contract Number:
AC52-07NA27344
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Chemical Physics Letters
Additional Journal Information:
Journal Volume: 678; Journal Issue: C; Related Information: CHORUS Timestamp: 2017-12-13 07:43:48; Journal ID: ISSN 0009-2614
Publisher:
Elsevier
Country of Publication:
Netherlands
Language:
English

Citation Formats

Manaa, M. Riad. Determination of adiabatic ionization potentials and electron affinities of energetic molecules with the Gaussian-4 method. Netherlands: N. p., 2017. Web. doi:10.1016/j.cplett.2017.04.038.
Manaa, M. Riad. Determination of adiabatic ionization potentials and electron affinities of energetic molecules with the Gaussian-4 method. Netherlands. doi:10.1016/j.cplett.2017.04.038.
Manaa, M. Riad. Thu . "Determination of adiabatic ionization potentials and electron affinities of energetic molecules with the Gaussian-4 method". Netherlands. doi:10.1016/j.cplett.2017.04.038.
@article{osti_1413071,
title = {Determination of adiabatic ionization potentials and electron affinities of energetic molecules with the Gaussian-4 method},
author = {Manaa, M. Riad},
abstractNote = {},
doi = {10.1016/j.cplett.2017.04.038},
journal = {Chemical Physics Letters},
number = C,
volume = 678,
place = {Netherlands},
year = {Thu Jun 01 00:00:00 EDT 2017},
month = {Thu Jun 01 00:00:00 EDT 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1016/j.cplett.2017.04.038

Save / Share:
  • A set of 146 well-established ionization potentials and electron affinities is presented. This set, referred to as the G2 ion test set, includes the 63 atoms and molecules whose ionization potentials and electron affinities were used to test Gaussian-2 (G2) theory [J. Chem. Phys. {bold 94}, 7221 (1991)] and 83 new atoms and molecules. It is hoped that this new test set combined with the recently published test set of enthalpies of neutral molecules [J. Chem. Phys. {bold 106}, 1063 (1997)] will provide a means for assessing and improving theoretical models. From an assessment of G2 and density functional theoriesmore » on this test set, it is found that G2 theory is the most reliable method. It has an average absolute deviation of 0.06 eV for both ionization potentials and electron affinities. The two modified versions of G2 theory, G2(MP2,SVP) and G2(MP2) theory, have average absolute deviations of 0.08{endash}0.09 eV for both ionization potentials and electron affinities. The hybrid B3LYP density functional method has the smallest average absolute deviation (0.18 eV) of the seven density functional methods tested for ionization potentials. The largest deviation for the density functional methods is for the ionization potential of CN ({gt}1thinspeV). The BLYP density functional method has the smallest average absolute deviation (0.11 eV) of the seven density functional methods tested for electron affinities, while the BPW91, B3LYP, and B3PW91 methods also do quite well. {copyright} {ital 1998 American Institute of Physics.}« less
  • Using density functional method, we have obtained predictions of ionization energies and electron affinities for CH[sub 3]S and CH[sub 2]SH. These predictions are in good accord with experimental values and theoretical values based on the Gaussian-2 theory.
  • A direct method (D-Delta-MBPT(2)) to calculate second-order ionization potentials (IPs), electron affinities (EAs), and excitation energies is developed. The Delta-MBPT(2) method is defined as the correlated extension of the Delta-HF method. Energy differences are obtained by integrating the energy derivative with respect to occupation numbers over the appropriate parameter range. This is made possible by writing the second-order energy as a function of the occupation numbers. Relaxation effects are fully included at the SCF level. This is in contrast to linear response theory, which makes the D-Delta-MBPT(2) applicable not only to single excited but also higher excited states. We showmore » the relationship of the D-Delta-MBPT(2) method for IPs and EAs to a second-order approximation of the effective Fock-space coupled-cluster Hamiltonian and a second-order electron propagator method. We also discuss the connection between the D-Delta-MBPT(2) method for excitation energies and the CIS-MP2 method. Finally, as a proof of principle, we apply our method to calculate ionization potentials and excitation energies of some small molecules. For IPs, the Delta-MBPT(2) results compare well to the second-order solution of the Dyson equation. For excitation energies, the deviation from EOM-CCSD increases when correlation becomes more important. When using the numerical integration technique, we encounter difficulties that prevented us from reaching the Delta-MBPT(2) values. Most importantly, relaxation beyond the Hartree Fock level is significant and needs to be included in future research.« less