Coupled Electron-Nuclear Dynamics on H2(+) Within Time-Dependent Born-Oppenheimer Approximation.

Quantum dynamical behaviour of H2(+) in the presence of linearly polarized, ultrashort, intense, infrared laser pulse has been studied by numerically solving the time-dependent Schrödinger equation with nuclear motion restricted in one-dimension along the direction of laser polarization and electronic motion in three-dimensions. Based on time-dependent Born-Oppenheimer approximation, we have constructed time-dependent potentials for the ground electronic state 1sσg of H2(+). Subsequent nuclear dynamics is then carried out on these field-dressed potential energy surfaces and the dissociation dynamics is investigated. Our analysis reveal that although the electronic longitudinal degree of freedom plays the major role in governing the dissociation dynamics, contribution from the electronic transverse degree of freedom should also have to be taken into account in order to obtain accurate results. Also, modelling electron-nuclei Coulomb interaction in an one dimensional calculation with artificially chosen constant softening parameter leads to discrepancy with the exact results. Comparing our results with other quantum and classical dynamical studies showed a good agreement with exact results.