Associate Professor of Physics and Chemistry

### About

Newly emerging "electron correlation" devices made out of transition metal oxide heterostructures (Sr(Zr)TiO3), battery materials (LiMPO4 (with M = Mn, Fe, Co, and Ni) and new molecular magnets used in quantum computing are at the heart of new experimental developments in materials and chemical sciences. Such experimental progress poses many questions to our theoretical understanding. The answers can be found using a combination of modeling and theory to support the experiment. In our group, to tackle these important questions we are developing controlled, reliable, and systematically improvable theoretical methods that describe correlation effects and are able to treat solids and large molecules realistically.

Our work is interdisciplinary in nature and we connect three fields, chemistry, physics and materials science. Our goal is to develop theoretical tools that give access to directly experimentally relevant quantities. We develop and apply codes that describe two types of electronic motion (i) weakly correlated electrons originating from the delocalized "wave-like" s- and p-orbitals responsible for many electron correlation effects in molecules and solids that do not contain transition metal atoms (ii) strongly correlated electrons residing in the d- and f-orbitals that remain localized and behave "particle-like" responsible for many very interesting effects in the molecules containing d- and f-electrons (transition metal nano-particles used in catalysis, nano-devices with Kondo resonances and molecules of biological significance - active centers of metalloproteins). The mutual coupling of these two types of electronic motion is challenging to describe and currently only a few theories can properly account for both types of electronic correlation effects simultaneously.

Available research projects in the group involve (1) working on a new theory that is able to treat weakly and strongly correlated electrons in molecules with multiple transition metal centers with applications to molecular magnets and active centers of enzymes (2) developing a theory for weakly correlated electrons that is able to produce reliable values of band gaps in semiconductors and heterostructures used in solar cells industry (3) applying the QM/QM embedding theories developed in our group to catalysis on transition metal-oxide surfaces and (4) applying the embedding formalism to molecular conductance problems in order to include correlation effects.

**Recent Publications**

Chebyshev Polynomial Representation of Imaginary Time Response Functions, (A. Rusakov, D. Zgid, E. Gull, I. Krivenko and S. Iskakov), *Phys Rev.* **B** **98**, 075127 (2018).

Stochastic Self-Consistent Second-Order Green’s Function Method for Correlation Energies of Large Electronic Systems, (D. Neuhauser, D. Zgid and R. Baer), *J. Chem. Theory Comput.* **13 **(11), 5396-5403 (2017).

Combining Density Functional Theory and Green’s Function Theory: Range-Separated, Nonlocal, Dynamic, and Orbital-Dependent Hybrid Functional, (D. Zgid and A. Kananenka), *J. Chem. Theory Comput.* **13 **(11), 5317-5331 (2017).

Testing Self-Energy Embedding Theory in Combination with GW, (A. Shee, D. Zgid, E. Gull, J. Li and T. Lan), *Phys. Rev. ***B** **96** (15), 155106 (2017).

Towards the Solution of the Many-Electron Problem in Real Materials: Equation of State of the Hydrogen Chain with State-of-the-Art Many-Body Methods, (D. Ceperley, E. Gull, G. K-. L. Chan, J. Gomez, M. Motta… D. Zgid…), *Phys. Rev. X* **7** (3), 031059 (2017).

Generalized Self-Energy Embedding Theory, (D. Zgid and T. Lan), *J. Phys. Chem. Lett.* **8** (10), 2200-2205 (2017).

Finite Temperature Quantum Embedding Theories for Correlated Systems, (D. Zgid and E. Gull), *New J. Phys.* **19** (2), 023047 (2017).

**Field(s) of Study**

**Theoretical Condensed Matter Physics**
**Theoretical Atomic, Molecular & Optical Physics**