should be responsible for the VSC resonance enhancement effects, and will be treated by FGR rate theory. The third line in Eq. A2 describes Holstein-type of systembath coupling (diagonal coupling), in which the term With the above analysis, the rate constant is ready to be written down as 50 In the last line of Eq. A8, we used the definition of the effective spectral density function (Eq. 11) which is in the discrete form. The broadening function G(ω -ω 0 ) is a Gaussian distribution centered around ω 0 , defined as