Transmission through the asymmetric rectangular barrier of Section 3.2. The thermal reaction rate constant is given as a function of temperature measured in units of the barrier height [], where . The rate constants are obtained using the exact QM transmission probability and energy levels (circles/solid line), the QC transmission probability evaluated at the exact QM energy levels (triangles/dot-dash) and at the QC energy levels of the isolated reactant well (squares/dash). The insert shows on the linear scale for wide range of temperatures.