Ab initio molecular dynamics simulation on H2O+C+ reaction

The production mechanism for interstellar ion HOC+ and its isomer HCO+ from the ion-molecule reaction H2O+C+ was studied using ab initio molecular dynamics. Classical trajectories were calculated by the direct dynamics simulation technique introduced by Takayanagi and Taketsugu (2006) [17] at the B3LYP/6-311++G(d,p) level of theory. The accuracy of the B3LYP-level potential-energy surface was checked by comparison with more accurate CCSD-level calculations. More than 200 trajectories were integrated, and it was confirmed that the reaction H2O+C+ mostly produces HOC+, even though the energy level of HCO+ is lower than that of HOC+.