Appendix
A.  Superposition state of an asymmetric double-well system in vacuum
        Let us consider an asymmetric double-well system with two local minimum states\(|0\rangle\)and \(|1\rangle\)for the wells 0 and 1, respectively, in vacuum (Figure S2 (a)). For an unperturbed system, we define the Hamiltonian operator as \(H_0\) . The eigenstates are  \(|0\rangle\)and \(|1\rangle\) with respect to the atomic orbitals and their eigenvalues are E0 and E1. The approximate solution \(\psi = c_0 |0\rangle + c_1 |1\rangle\), corresponding to the molecular orbital, of the double-well system satisfies the Schrödinger equation