David O'Regan
Assistant Professor, Physics

Biography

I completed my PhD at the Cavendish Laboratory, University of Cambridge in 2011, after which I carried out post-doctoral research there, and then at the École Polytechnique Fédérale de Lausanne (EPFL), Switzerland. I am now Assistant Professor in Condensed Matter Theory at TCD's School of Physics.

Publications and Further Research Outputs

Peer-Reviewed Publications

Artacho, Emilio, O'Regan, David D., Quantum mechanics in an evolving Hilbert space, Physical Review B, 95, (11), 2017, p5155 Journal Article, 2017

O'Regan D., Teobaldi G., Teobaldi G., Optimization of constrained density functional theory, Physical Review B - Condensed Matter and Materials Physics, 94, (3), 2016 Journal Article, 2016 DOI

Turban, D.H.P., Teobaldi, G., O'Regan, D.D., Hine, N.D.M., Supercell convergence of charge-transfer energies in pentacene molecular crystals from constrained DFT, Physical Review B - Condensed Matter and Materials Physics, 93, (16), 2016 Journal Article, 2016

, Inapplicability of exact constraints and a minimal two-parameter generalization to the DFT+$U$ based correction of self-interaction error, Phys. Rev. B, 2016 Journal Article, 2016

Hanlon D, Backes C, Doherty E, Cucinotta CS, Berner NC, Boland C, Lee K, Harvey A, Lynch P, Gholamvand Z, Zhang S, Wang K, Moynihan G, Pokle A, Ramasse QM, McEvoy N, Blau WJ, Wang J, Abellan G, Hauke F, Hirsch A, Sanvito S, O'Regan DD, Duesberg GS, Nicolosi V, Coleman JN, Liquid exfoliation of solvent-stabilized few-layer black phosphorus for applications beyond electronics., Nature communications, 6, 2015, p8563 Journal Article, 2015 DOI TARA - Full Text

Teobaldi, Gilberto, Morgan, Benjamin J., Regan, David D. O., Hine, Nicholas D., Mostofi, Arash A., Subspace-corrected functionals for linear-scaling density functional theory simulation of extended energy storage interfaces, Abstracts of Papers of the American Chemical Society, 248, 2014 Journal Article, 2014

Weber, C., Cole, D.J., O'Regan, D.D., Payne, M.C., Renormalization of myoglobin-ligand binding energetics by quantum many-body effects, Proceedings of the National Academy of Sciences of the United States of America, 111, (16), 2014, p5790-5795 Journal Article, 2014

Weber, C., O'Regan, D.D., Hine, N.D.M., Littlewood, P.B., Kotliar, G., Payne, M.C., Importance of many-body effects in the kernel of hemoglobin for ligand binding, Physical Review Letters, 110, (10), 2013 Journal Article, 2013 DOI URL

Heiss, M., Fontana, Y., Gustafsson, A., Wüst, G., Magen, C., O'Regan, D.D., Luo, J.W., Ketterer, B., Conesa-Boj, S., Kuhlmann, A.V., Houel, J., Russo-Averchi, E., Morante, J.R., Cantoni, M., Marzari, N., Arbiol, J., Zunger, A., Warburton, R.J., Fontcuberta I Morral, A., Self-assembled quantum dots in a nanowire system for quantum photonics, Nature Materials, 12, (5), 2013, p439-444 Journal Article, 2013 DOI URL

O'Regan, D. D., Dubois, S. M. M., Umari, P., Haynes, P. D., Report on Workshop: "Efficient localised orbitals for large systems, strong correlations and excitations", Psi-k Network Newsletter, 113, 2012, p11---24 Journal Article, 2012

O'Regan, D. D., Oregan, D. D., A Numerical Study of Geometric Corrections for Representation Optimisation, Optimised Projections for the Ab Initio Simulation of Large and Strongly Correlated Systems, 2012, p151-169 Journal Article, 2012

O'Regan, D.D., Payne, M.C., Mostofi, A.A., Generalized Wannier functions: A comparison of molecular electric dipole polarizabilities, Physical Review B - Condensed Matter and Materials Physics, 85, (19), 2012 Journal Article, 2012 URL DOI

Cole, D.J., O'Regan, D.D., Payne, M.C., Ligand discrimination in myoglobin from linear-scaling DFT+ U, Journal of Physical Chemistry Letters, 3, (11), 2012, p1448-1452 Journal Article, 2012 URL DOI

O'Regan, D. D., Oregan, D. D., Tensorial Aspects of Calculating Hubbard U Interaction Parameters, Optimised Projections for the Ab Initio Simulation of Large and Strongly Correlated Systems, 2012, p171-197 Journal Article, 2012

O'Regan, D. D., Oregan, D. D., An Introduction to Linear-Scaling Ab Initio Calculations, Optimised Projections for the Ab Initio Simulation of Large and Strongly Correlated Systems, 2012, p1-35 Journal Article, 2012

Cole, D. J., O'Regan, D. D., Lee, L. P., Chau, P. L., Skylaris, C. K., Payne, M. C., Biomolecular simulation with the linear-scaling DFT code ONETEP, Abstracts of Papers of the American Chemical Society, 243, 2012, p1 Journal Article, 2012

O'Regan, D. D., Oregan, D. D., Linear-Scaling DFT plus U for Large Strongly-Correlated Systems, Optimised Projections for the Ab Initio Simulation of Large and Strongly Correlated Systems, 2012, p37-63 Journal Article, 2012

O'Regan, D. D., Oregan, D. D., Geometric Aspects of Representation Optimisation, Optimised Projections for the Ab Initio Simulation of Large and Strongly Correlated Systems, 2012, p125-149 Journal Article, 2012

Weber, C., O'Regan, D.D., Hine, N.D.M., Payne, M.C., Kotliar, G., Littlewood, P.B., Vanadium dioxide: A peierls-mott insulator stable against disorder, Physical Review Letters, 108, (25), 2012 Journal Article, 2012 DOI URL

O'Regan, D.D., Hine, N.D.M., Payne, M.C., Mostofi, A.A., Linear-scaling DFT+U with full local orbital optimization, Physical Review B - Condensed Matter and Materials Physics, 85, (8), 2012 Journal Article, 2012 DOI URL

O'Regan, D. D., Oregan, D. D., Optimised Projections for the Ab Initio Simulation of Large and Strongly Correlated Systems Discussion and Conclusion, Optimised Projections for the Ab Initio Simulation of Large and Strongly Correlated Systems, 2012, p199-202 Journal Article, 2012

O'Regan, D.D., Payne, M.C., Mostofi, A.A., Subspace representations in ab initio methods for strongly correlated systems, Physical Review B - Condensed Matter and Materials Physics, 83, (24), 2011 Journal Article, 2011 URL DOI

O'Regan, D.D., Hine, N.D.M., Payne, M.C., Mostofi, A.A., Projector self-consistent DFT+U using nonorthogonal generalized Wannier functions, Physical Review B - Condensed Matter and Materials Physics, 82, (8), 2010 Journal Article, 2010 URL DOI

Research Expertise

Description

My research is dedicated to the development and application of novel, accurate, but computationally tractable methodology for atomistic electronic structure simulations, both of solid state materials and molecular systems. I focus on the interface between techniques for treating large length-scales, the strong electronic correlations almost ubiquitous in systems of technological interest, and theoretical spectroscopy. I am actively involved in the development of linear-scaling density functional theory. Here, I implement and improve corrective approaches such as DFT+U, constrained DFT and DFT+DMFT, as well as researching new Wannierisation and time propagation (TDDFT) algorithms. I maintain a long-term programme in the development of tractable and easily-used methods moving beyond Kohn-Sham DFT, via the density-matrix and Green's function, not only for spectra but for energies and their derivatives. I'm interested in multiferroic and multiple-valence properties, generally, and optical, magneto-optical, and photoemission spectroscopies. A particular focus is placed on these properties as exhibited by transition-metal comprising materials, complexes, and nanostructures. At present, applications of these materials to new high-density energy and data-storage technologies are receiving some attention. I collaborate extensively with leading scientists from diverse fields including nanostructure fabrication, high-performance computing, and condensed matter theory.

Keywords

Advanced electronic materials; ATOMISTIC SIMULATION; BIOSCIENCE; CHIROPTICAL SPECTROSCOPY; COMPUTER MODELING AND SIMULATION; CONSTRAINED DENSITY-FUNCTIONAL THEORY; DENSITY-FUNCTIONAL THEORY; DYNAMICAL MEAN-FIELD THEORY; Functional Materials; HARD MAGNETIC MATERIALS; LINEAR-SCALING DENSITY-FUNCTIONAL THEORY; MAGNETIC MATERIALS; MANY-BODY PERTURBATION THEORY; MANY-BODY THEORY; MATERIALS SCIENCE; METALLOPROTEINS; nanoscience; Organometallic Chemistry; REDUCED DENSITY-MATRIX FUNCTIONAL THEORY; SEMICONDUCTOR DEVICES AND MATERIALS; Theoretical Physics; THEORETICAL SPECTROSCOPY; TIME-DEPENDENT DENSITY-FUNCTIONAL THEORY