  Kramers-Grote-Hynes factor is the key nonequilibrium contribution to rate
constant of a reaction over and above the transition state theory rate in the
spatial limited regime. Wolynes in eighties introduced a quantum correction to
the overall rate coefficient. This is responsible for tunneling and quantum
enhancement of rate at low temperature. However, its validity is restricted to
activated tunneling region or above crossover temperature. Based on a quantum
formulation of the normal mode analysis, we suggest a generalization of Wolynes
factor and a consequent multidimensional transition state rate expression which
are valid in the deep tunneling region down to zero degree Kelvin.
