The synergistic effects of molecular packing and external electric fields (EEFs, including axial and nonaxial fields) on the internal charge reorganization energies (λ) of typical p-type SMOS have been investigated. Combined quantum and molecular mechanics calculations show that, for all-ring-fused rigid molecules single-molecule approximation and neglect of EEFs are adequate for computing λ, while for nonrigid molecules with inter-ring carbon-carbon (IRCC) linkers, the above simplifications may cause a significant deviation from the actual λ. For nonrigid molecules, solid-state packing can prevent "bad" EEFs (Fz and Fyz) from enhancing λ (adverse to charge transfer), while it allows λ to be greatly reduced (in favor of charge transfer) if "good" EEFs (Fx, Fxy, Fxz and Fxyz) are imposed. Last, a simple strategy that can divide λ into each subring contribution for IRCC-linked molecules has been proposed.