Figure 1. Schematics.

(a) Schematic for the correspondence between the phases of TBSBM and the states in charge separation. In the localized phase, the spin is polarized in one potential valley formed by the vibrational modes, corresponding to the situation that the electron and hole are strongly bound with each other. In the delocalized phase, the spin is equally populated in two valleys, equivalent to the case that the coherence of electron and hole is completely quenched. In between, both the local and nonlocal coherence are retained. (b) The two kinds of optimal phonon basis for the DMRG calculations. The AOPB is shown which takes into account the phonon bases with shifted displacements⁴³. The SOPB is shown which considers the globally lowest phonon bases.