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Gallium phosphides GA m P n ( m + n = 2–5) and their anions: Structures, electron affinities, and vibrational frequencies
Author(s) -
Guo Ling,
Wu Haishun
Publication year - 2005
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.20779
Subject(s) - electron affinity (data page) , gallium , basis set , bond length , density functional theory , band gap , chemistry , adiabatic process , electron , gallium phosphide , atomic physics , analytical chemistry (journal) , crystallography , computational chemistry , molecule , crystal structure , physics , condensed matter physics , quantum mechanics , chromatography , organic chemistry , thermodynamics
Geometries, electronic states, and electron affinities of Ga m P n and Ga m P − n( m + n = 2–5) clusters have been examined using four hybrid and pure density functional theory (DFT) methods. Structural optimization and frequency analyses are performed with the basis of a 6‐311+G (2df) one‐particle basis set. The geometries are fully optimized with each DFT method independently. Three types of energy separations reported in this work are the adiabatic electron affinity (EA ad ), the vertical electron affinity (EA vert ), and the vertical detachment energy (VDE). The calculation results show that the singlet structures have higher symmetry than that of doublet structures. The best method for predicting molecular structures was found to be BLYP, while other methods generally underestimated bond lengths. The most reliable adiabatic electron affinities and vertical detachment energy, obtained at the BP86 and B3LYP level of theory, are predicted to be 2.22 and 2.10 eV (GaP), 2.51 and 2.46 eV (Ga 2 P), 1.86 and 1.94 eV (GaP 2 ), 1.96 and 2.27 eV (GaP 3 ), 1.76 and 1.99 eV (Ga 3 P), 1.79 and 2.14 eV (Ga 2 P 2 ), 2.85 and 3.67 eV (GaP 4 ), 2.08 and 2.10 eV (Ga 4 P), 2.90 and 3.17 eV (Ga 2 P 3 ), and 2.70 and 3.37 eV (Ga 3 P 2 ), respectively. Those for Ga 2 P, Ga 3 P, Ga 2 P 2 , Ga 4 P, GaP 4 , Ga 2 P 3 , and Ga 3 P 2 are in good agreement with experiment, but the predicted EA ad values for GaP, Ga 2 P, GaP 2 , and GaP 3 are larger than the available experimental values. For the vibrational frequencies of the Ga m P n series, the B3LYP method produces good predictions with the average error only ∼10 cm −1 from available experimental and theoretical values. The other three methods overestimate or underestimate the vibrational frequencies, with the worst predictions given by the BLYP method. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006