@article {2591,
	title = {An evaluation of exchange-correlation functionals for the calculations of the ionization energies for atoms and molecules},
	journal = {Journal of Electron Spectroscopy and Related Phenomena},
	volume = {171},
	number = {1-3},
	year = {2009},
	note = {ISI Document Delivery No.: 452BQTimes Cited: 6Cited Reference Count: 82Segala, Maximiliano Chong, Delano P.},
	month = {Apr},
	pages = {18-23},
	type = {Article},
	abstract = {In this paper, ionization energies of gas-phase atoms and molecules are calculated by energy-difference method and by approximate transition-state models with density functional theory (DFT). To determine the best functionals for ionization energies, we first study the H to Ar atoms. An approximation is used in which the electron density is first obtained from Kohn-Sham computations with an exchange-correlation potential V-xc known as statistical average of orbital potentials (SAOP), after which the energy is computed from that density with 59 different exchange-correlation energy functionals E-xc. For the 18 atoms, the best E-xc functional providing an average absolute deviation (AAD) of only 0.110 eV is one known as the Krieger-Chen-lafrate-Savin functional modified by Krieger, Chen, Iafrate, and Kurth, if one uses the spin-polarized spherical atom description. On the other hand, if one imposes the condition of integer-electrons, the best functional is the Becke 1997 functional modified by Wilson, Bradley, and Tozer, with an AAD of 0.107 eV, while several other functionals perform almost as well. For molecules, we can achieve an accuracy of AAD = 0.21 eV for valence VIPs of nonperhalo molecules with Delta E(V-xc = SAOP;PBEO) using integer-electron description. For perhalo molecules our best approach is Delta E(V-xc from either E-xc or SAOP;mPW1PW) with full symmetry to obtain an AAD = 0.24 eV. (c) 2009 Elsevier B.V. All rights reserved.},
	keywords = {ADJUSTABLE-PARAMETERS, ASYMPTOTIC-BEHAVIOR, DFT, Energy-difference method, EXCITATION-ENERGIES, GENERALIZED GRADIENT APPROXIMATION, HE(II) PHOTOELECTRON-SPECTRA, Integer-electron, Ionization energy, models, ORBITAL MODEL POTENTIALS, ORGANIC-MOLECULES, PHOTO-ELECTRON SPECTRA, Slater-type orbitals, Spin-polarized spherical atom, STATISTICAL AVERAGE, TRANSITION-STATE},
	isbn = {0368-2048},
	url = {<Go to ISI>://000266515000002},
	author = {Segala, M. and Chong, D. P.}
}
@article {1602,
	title = {Search for suitable approximation methods for fullerene structure and relative stability studies: Case study with C<sub>50</sub>},
	journal = {J. Chem. Phys.},
	volume = {125},
	number = {9},
	year = {2006},
	note = {ISI Document Delivery No.: 081XSTimes Cited: 13Cited Reference Count: 48Tian, Wei Quan Feng, Ji-Kang Wang, Yan Alexander Aoki, Yuriko},
	month = {Sep},
	pages = {094105},
	type = {Article},
	abstract = {<p>Local density approximation (LDA), several popular general gradient approximation (GGA), hybrid module based density functional theoretical methods: SVWN, BLYP, PBE, HCTH, B3LYP, PBE1PBE, B1LYP, and BHandHLYP, and some nonstandard hybrid methods are applied in geometry prediction for C-60 and C-70. HCTH with 3-21G basis set is found to be one of the best methods for fullerene structural prediction. In the predictions of relative stability of C-50 isomers, PM3 is an efficient method in the first step for sorting out the most stable isomers. HCTH with 3-21G predicts very good geometries for C-50, similar to the performance of B3LYP/6-31G(d). The gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital from the predictions of all the density functional theory methods has the following descending order: E-gap(half-and-half hybrid)\&gt; E-gap(B3LYP)\&gt; E-gap(HCTH)(GGA)\&gt; E-gap(SVWN)(LDA). (c) 2006 American Institute of Physics.</p>},
	keywords = {ADJUSTABLE-PARAMETERS, BUCKMINSTERFULLERENE, C-70, DENSITY-FUNCTIONAL THEORY, ELECTRON-DIFFRACTION, ENERGIES, GENERALIZED GRADIENT APPROXIMATION, MOLECULAR-STRUCTURE, PERFORMANCE, PHASE, SEMIEMPIRICAL METHODS},
	isbn = {0021-9606},
	url = {<Go to ISI>://000240351500008},
	author = {W. Q. Tian* and J.-K. Feng and Wang, Y. A. and Aoki, Y.}
}
