Structures, vibrational frequencies, and electron affinities of SF 5O n/SF 5O n− ( n = 1–3)

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The molecular structures, vibrational frequencies, and electron affinities of the SF 5O n /SF 5O n − ( n = 1–3) species have been examined with four hybrid density functional theory (DFT) methods. The basis set used in this work is of double-ζ plus polarization quality with additional diffuse s- and p-type functions, denoted DZP++. The geometries are fully optimized with each DFT method independently. The SF 5O n ( n = 1–3) species should be potential greenhouse gases. The anion SF 5O 2 − with C s symmetry has a 3A″ electronic state, and the neutral SF 5O 3 with 2A″ electronic state has C s symmetry. The anions SF 5O 2 − and SF 5O 3 − should be regarded as SF 5 −·O 2 and SF 5O −·O 2 complexes, respectively. Three different types of the neutral–anion energy separation presented in this work are the adiabatic electron affinity (EA ad), the vertical electron affinity (EA vert), and the vertical detachment energy (VDE). The EA ad values predicted by the B3PW91 method are 5.22 (SF 5O), 4.38 (SF 5O 2), and 3.61 eV (SF 5O 3). Compared with the experimental vibrational frequencies, the BHLYP method overestimates the frequencies, and the other three methods underestimate the frequencies. The bond dissociation energies D e (SF 5O n → SF 5O n − m + O m) for the neutrals SF 5O n and D e (SF 5O n − → SF 5O n − m − + O m and SF 5O n − → SF 5O n − m + O m −) for the anions SF 5O n − are reported.