with b ij (t) = e -( j -i )/k B T for j > i , and b ij (t) = 1 for j ≤ i , where k B is Boltzmann's constant, and T is the temperature of the system, which is assumed to be constant during the non-adiabatic dynamics. Eq. ( ) considers only the positive probability flux. Finally, a switch from the state |Φ i (r, R(t)) to any other state, |Φ j (r, R(t)) , is accepted only when