Time-dependent density functional study of the electronic potential energy curves and excitation spectrum of the oxygen molecule

Abstract

Time-dependent density functional study of the electronic potential energy curves and excitation spectrum of the oxygen molecule Article (Unspecified) http://sro.sussex.ac.uk Guan, Jingang, Wang, Fan, Ziegler, Tom and Cox, Hazel (2006) Time-dependent density functional study of the electronic potential energy curves and excitation spectrum of the oxygen molecule. Journal of Chemical Physics, 125 (4). p. This version is available from Sussex Research Online: http://sro.sussex.ac.uk/583/ This document is made available in accordance with publisher policies and may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher's version. Please see the URL above for details on accessing the published version. Copyright and reuse:Sussex Research Online is a digital repository of the research output of the University.Copyright and all moral rights to the version of the paper presented here belong to the individual author(s) and/or other copyright owners. To the extent reasonable and practicable, the material made available in SRO has been checked for eligibility before being made available.Copies of full text items generally can be reproduced, displayed or performed and given to third parties in any format or medium for personal research or study, educational, or not-for-profit purposes without prior permission or charge, provided that the authors, title and full bibliographic details are credited, a hyperlink and/or URL is given for the original metadata page and the content is not changed in any way.Time-dependent density functional study of the electronic potential energy curves and excitation spectrum of the oxygen molecule Orbital energies, ionization potentials, molecular constants, potential energy curves, and the excitation spectrum of O 2 are calculated using time-dependent density functional theory ͑TDDFT͒ with Tamm-Dancoff approximation ͑TDA͒. The calculated negative highest occupied molecular orbital energy ͑− HOMO ͒ is compared with the energy difference ionization potential for five exchange correlation functionals consisting of the local density approximation ͑LDAxc͒, gradient corrected Becke exchange plus Perdew correlation ͑B 88X +P 86C ͒, gradient regulated asymptotic correction ͑GRAC͒, statistical average of orbital potentials ͑SAOP͒, and van Leeuwen and Baerends asymptotically correct potential ͑LB94͒. The potential energy curves calculated using TDDFT with the TDA at internuclear distances from 1.0 to 1.8 Å are divided into three groups according to the electron configurations. The 1 u 4 1 g 2 electron configuration gives rise to the X 3 ⌺ g − , a 1 ⌬ g , and b 1 ⌺ g + states; the 1 u 3 1 g 3 electron configuration gives rise to the c 1 ⌺ u − , C 3 ⌬ u , and A 3 ⌺ u + states; and the B 3 ⌺ u − , A 1 ⌬ u , and f 1 ⌺ u + states are determined by the mixing of two or more electron configurations. The excitation spectrum of the oxygen molecule, calculated with the aforementioned exchange correlation functionals, shows that ...

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