Quantum embedding for excited states in molecular and periodic systems

Projection-based quantum embedding methodologies provide a framework for performing DFT-in-DFT and wavefunction-in-density functional theory (WF-in-DFT) calculations. The previous application of using absolute localization on the ground states of molecular systems¹ and periodic systems² showed high accuracy and improved computational efficiency.

In this work, we extend the absolute localization method to study localized excited states in molecular and periodic systems. We show the accurate embedding results on small organic molecules and green fluorescent protein (GFP). We are further extending our methods to periodic systems. Ray et al.³ found that different density functionals have to be used for CsMI₃ (M = Ge, Sn, Pb, Mg, Ca, Sr and Ba) to reproduce the experimental band gaps. Not a single exchange-correlation functional can give consistently good results among these inorganic perovskites.³ We discuss our progress of making periodic WF-in-DFT embedding methods applicable to such systems.


1. Chulhai, D. V.; Goodpaster, J. D. J. Chem. Theory Comput. 2017, 13, 1503-1508.
2. Chulhai, D. V.; Goodpaster, J. D. J. Chem. Theory Comput. 2018, 14, 1928–1942.
3. Ray, D.; Clark, C.; Pham, H. Q.; Borycz, J.; Holmes, R. J.; Aydil, E. S.; Gagliardi, L. J. Chem. Phys. C. 2018, 122, 7838–7848.