Ab initio CASSCF and MRSDCI calculations of the (C6H6)2+ radical

S 1 –S vibronic spectra of benzene clusters revisited. II. The trimer

“…Theoretical studies have provided the stabilization energies for various benzene clusters, [15][16][17][18][19][20][21][22][23][24][25][26][27] including their cations. [40][41][42] Binding energies of small benzene clusters have been reported by Krause et al 9 By using two-color R2PI, they have measured the photoionization efficiency curves of the neutral clusters to determine the respective adiabatic ionization potentials and the appearance potential of the metastable dissociation channel of each cluster ion. Based on these data, they calculated the binding energies.…”

“…This would be explained by large structural change from the neutral to the ionic state in the benzene clusters. According to the theoretical studies by Miyoshi and co-workers, 41,42 the global minima for the dimer and trimer cations are at C 2h and C 2v geometries, respectively, in which the benzene moieties are arranged parallel. Obviously, these ion structures are much different from the T-shaped or cyclic form in the neutral state.…”

Direct ab initio molecular dynamics (MD) study of the ionization on a benzene dimer

“…The electronic states of the neutral benzene dimer and benzene dimer cation have been well understood. [20][21][22][23][24][25][26][27][28][29][30][31][32] However, the dynamics feature for the formation mechanism of the benzene dimer cation following the ionization of the neutral benzene dimer is scarcely known because there is no theoretical study on the reaction dynamics.…”

Electronic structure of the benzene dimer cation

“…[37][38][39][40][41][42][43] Several computational studies have investigated the ground state structures of the dimer cation. 41,[43][44][45][46][47] Milosevich et al 44 suggested a displaced sandwich structure based on Hartree-Fock calculations. Møller-Plesset calculations of Hiraoka et al 41 put forward the t-shaped structure as the lowest isomer.…”

“…Density functional calculation predicts the ground state to have a sandwich structure. 43,47 The most exhaustive study to date is due to Miyoshi et al, 45,46 who characterized both ground and excited states of the dimer cation. In the earlier work, 45 they employed the complete active space self-consistent field ͑CASSCF͒ and multireference configuration interaction with singles and doubles ͑MR-CISD͒ methods to investigate the electronic structure of sandwich, displaced sandwich, and t-shaped isomers.…”