Quantum mechanical reactive scattering by a multiconfigurational time-dependent self-consistent field (MCTDSCF) approach

The major obstacle to the description of systems containing a large number of degrees of freedom is the exponential increase of computational time and effort with dimensionality. A strategy is presented to overcome this obstacle as well as the shortcoming of the omission of correlations, while still maintaining the simplicity and strengths of a mean-field description, based upon identifying the crucial dynamical correlations and incorporating them with multiconfigurations. The collinear reactive scattering of H + H₂ illustrates the techniques involved and their adaptability, flexibility, and breadth of applicability. MCTDSCF simulations, constructed from time-dependent variational principles, are compared with the numerically exact solution of the Schrödinger equation; agreement is found.