The validity of time-dependent self-consistent field approximation for non-stationary vibrational bound states of quantum clusters

The time-dependent self-consistent field (TDSCF) approximation is applied to the coupled-mode vibrational dynamics of highly anharmonic quantum clusters, and its validity and accuracy for such systems are tested against exact quantum calculations. The calculations are pursued for bound but non-stationary states of collinear models of (Ne)3 and B(H2)2. It is found that for a short timescale (t ⩽ 1 ps) the TDSCF approximation is in excellent accord with the exact results. This suggests that TDSCF should be an attractive quantitative approach for the short timescale vibrational dynamics of highly anharmonic quantum clusters.