In principle, these issues can be addressed using more advanced electronic structure models, but application of such methods to periodic crystals of pharmaceuticalsized molecules is generally cost-prohibitive. A more pragmatic approach combines a conventional periodic DFT calculation using a generalized gradient approximation (GGA) with an intramolecular correction based on the difference between the baseline DFT functional and a more advanced model, computed for a gas-phase molecule. For example, using the B86bPBE+XDM functional, a GGA that includes a dispersion correction based on the exchange dipole moment (XDM), in combination with dispersion-corrected second-order Møller-Plesset perturbation theory (MP2D), the resulting polymorph stability rankings are consistent with experiment for ROY, acetamidobenzamide, and axitinib. A possible alternative solution to the π-delocalization problem comes in the form of density-corrected (DC-)DFT. In this approach, an approximate density functional Ẽ[ρ] is evaluated using a density ρ HF that is obtained at the Hartree-Fock (HF) level: