We set the sign correction factor ( ) ( ) I t λ as 1 or -1 to make the second term positive if l = a or negative if l a ≠ , where a denotes the active state of trajectory I. Then, the sign- corrected decoherence term always makes the electronic wave function collapse to the active state during decoherence processes. After introducing the sign correction, it is easy to prove that the sum of electronic populations is still conserved for each trajectory.