FIG. 1.

Electronic wavefunctions of the ground ${{}^2\Sigma }_{\text{g}}^{+}$ and first electronically excited ${{}^2\Sigma }_{\text{u}}^{+}$ states of ${\mathrm{H}}_2^{+}$ (left) and time-dependent electron density following the preparation of the superposition state $({\Phi }_{\mathrm{g}}+{\Phi }_{\mathrm{u}})/\sqrt{2}$ at t = 0 (right).