On the mechanism of the energy redistribution in the A2Ag(2Σg+) state of the HCCH+ ion

摘要: Abstract Using ab initio calculations large parts of the six-dimensional potential energy functions for all electronic components X 2 Π u A Σ g + and ′ states acetylene radical cation have been mapped. It has found that lowest doubles state HCCH is not trans-bent Ag ( ) state, as expected, but cis-bent shake-up which Franck-Condon active in ionization process because its long R CC distance. The only one Ag) minimum, Ā′ three minima (two B Bg)) on adiabatic functions. , are vibronically coupled conical intersection regions lying close to equilibrium structure by ν 3 4 5 modes, explains why experimentally observed vibrational bending modes lifetimes range 150 ps.