Skip to main content

Trinity College Dublin, The University of Dublin

Trinity Menu Trinity Search



You are here People

Dr. David O'Regan
Assistant Professor, Physics

Biography

I am an Assistant Professor in the School of Physics, where I currently serve as the Director of Teaching and Learning (Undergraduate), with an affiliation to CRANN. I am a SFI Principal Investigator and also an SFI Funded Investigator within the AMBER research centre. My research concerns development and innovation in the accurate and computationally increasingly routine quantum-mechanical description of the material world, specifically practical electronic structure simulation for solid state and molecular systems, together with theory and technique development in condensed matter physics and quantum materials discovery. I place an emphasis on materials for ICT and renewable energy. I also have a complementary long-term research interest in more abstract corrective functional development in density functional theory and in many-body theoretical spectroscopy methods. These activities take my Group and I from applications in novel magnets, complex oxides and metallic surfaces, and through to novel two-dimensional materials where we specialise in mechanics calculations, where in each case we enjoy working closely with many experimentalist partners overseas and closer to home.

I completed my PhD at the Cavendish Laboratory, University of Cambridge in 2011, after which I carried out post-doctoral research first there, and then at the École Polytechnique Fédérale de Lausanne (EPFL). Since arriving to Trinity I have served in Physics over different periods as Director of Examinations, Assistant DUTL, and Theoretical Physics Degree Course Coordinator, and in recent years have managed the School's summer research internship programme. At CRANN and AMBER, I organised for a successful seminar series for PostDocs and PhD students, and I continue to participate in a number of international applied research projects.

Publications and Further Research Outputs

Peer-Reviewed Publications

Alotibi S, Hickey BJ, Teobaldi G, Ali M, Barker J, Poli E, O'Regan DD, Ramasse Q, Burnell G, Patchett J, Ciccarelli C, Alyami M, Moorsom T, Cespedes O., Enhanced Spin-Orbit Coupling in Heavy Metals via Molecular Coupling., ACS Applied Materials & Interfaces, 13, (4), 2021, p5228-5234 Journal Article, 2021 DOI

Zhussupbekov, Kuanysh, Walshe, Killian, Walls, Brian, Ionov, Andrei, Bozhko, Sergei I., Ksenz, Andrei, Mozhchil, Rais N., Zhussupbekova, Ainur, Fleischer, Karsten, Berman, Samuel, Zhilyaev, Ivan, O'Regan, David D., Shvets, Igor V., Surface Modification and Subsequent Fermi Density Enhancement of Bi(111), The Journal of Physical Chemistry C, 125, (10), 2021, p5549-5558 Journal Article, 2021 DOI

Almohammed, S., Fularz, A., Zhang, F., Alvarez-Ruiz, D., Bello, F., O'Regan, D.D., Rodriguez, B.J., Rice, J.H., Flexing Piezoelectric Diphenylalanine-Plasmonic Metal Nanocomposites to Increase SERS Signal Strength, ACS Applied Materials and Interfaces, 12, (43), 2020, p48874-48881 Journal Article, 2020

Prentice J.C.A., Aarons J., Womack J.C., Allen A.E.A., Andrinopoulos L., Anton L., Bell R.A., Bhandari A., Bramley G.A., Charlton R.J., Clements R.J., Cole D.J., Constantinescu G., Corsetti F., Dubois S.M.-M., Duff K.K.B., Escartin J.M., Greco A., Hill Q., Lee L.P., Linscott E., O'Regan D.D., Phipps M.J.S., Ratcliff L.E., Serrano A.R., Tait E.W., Teobaldi G., Vitale V., Yeung N., Zuehlsdorff T.J., Dziedzic J., Haynes P.D., Hine N.D.M., Mostofi A.A., Payne M.C., Skylaris C.-K., The ONETEP linear-scaling density functional theory program, Journal of Chemical Physics, 152, (17), 2020 Journal Article, 2020 DOI

Roychoudhury S, Sanvito S, O'Regan DD., Neutral excitation density-functional theory: an efficient and variational first-principles method for simulating neutral excitations in molecules., Scientific reports, 10, (1), 2020, p8947 Journal Article, 2020 TARA - Full Text DOI

Orhan, O.K., O'Regan, D.D., First-principles Hubbard U and Hund's J corrected approximate density functional theory predicts an accurate fundamental gap in rutile and anatase TiO2, Physical Review B, 101, (24), 2020, p245137- Journal Article, 2020 DOI

Rangel, T., Del Ben, M., Varsano, D., Antonius, G., Bruneval, F., da Jornada, F.H., van Setten, M.J., Orhan, O.K., O'Regan, D.D., Canning, A., Ferretti, A., Marini, A., Rignanese, G.-M., Deslippe, J., Louie, S.G., Neaton, J.B., Reproducibility in G0W0 calculations for solids, Computer Physics Communications, 255, 2020, p107242- Journal Article, 2020 DOI

MacEnulty, Lórien, O'Regan, David D., Calculation of the Magnetostatic Energy in Spin Density Functional Theory, Journal of Undergraduate Reports in Physics, 30, (1), 2020, p100005 Journal Article, 2020 DOI

Orhan, O.K., O'Regan, D.D., Plasmonic performance of AuxAgyCu1-x-y alloys from many-body perturbation theory, Journal of Physics Condensed Matter, 31, (31), 2019 Journal Article, 2019 DOI

Backes C, Campi D, Szydlowska BM, Synnatschke K, Ojala E, Rashvand F, Harvey A, Griffin A, Sofer Z, Marzari N, Coleman JN, O'Regan DD., Equipartition of Energy Defines the Size-Thickness Relationship in Liquid-Exfoliated Nanosheets., ACS nano, 2019 Journal Article, 2019 TARA - Full Text DOI

Bello, F. and Orhan, O.K. and Abadia, N. and O'Regan, D.D. and Donegan, J.F., Material Characterization and Thermal Performance of Au Alloys in a Thin-Film Plasmonic Waveguide, OSA Technical Digest, CLEO: Applications and Technology 2019,, San Jose, California United States, , 5-10 May, (8749235), 2019, JTu2A.110- Conference Paper, 2019 URL DOI

Orhan, O.K., O'Regan, D.D., TDDFT+U: A critical assessment of the Hubbard U correction to exchange-correlation kernels and potentials, Physical Review B, 99, (16), 2019 Journal Article, 2019 DOI

Linscott, E.B., Cole, D.J., Payne, M.C., O'Regan, D.D., Role of spin in the calculation of Hubbard U and Hund's J parameters from first principles, Physical Review B, 98, (23), 2018 Journal Article, 2018 DOI

Roychoudhury, S. and O'Regan, D.D. and Sanvito, S., Wannier-function-based constrained DFT with nonorthogonality-correcting Pulay forces in application to the reorganization effects in graphene-adsorbed pentacene, Physical Review B, 97, (20), 2018, p085303- Journal Article, 2018 TARA - Full Text DOI

Linda A. Zotti, S. Sanvito, and David D. O'Regan, A simple descriptor for energetics at fcc-bcc metal interfaces, Materials & Design, 142, 2018, p158 - 165 Journal Article, 2018 DOI

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

Glenn Moynihan, Stefano Sanvito, and David D. O'Regan, Strain-induced Weyl and Dirac states and direct-indirect gap transitions in group-V materials, 2D Materials, 4, (4), 2017, p045018 Journal Article, 2017 TARA - Full Text DOI

David H. P. Turban, Gilberto Teobaldi, David D. O'Regan, and Nicholas D. M. Hine, Supercell convergence of charge-transfer energies in pentacene molecular crystals from constrained DFT, Physical Review B, 93, (16), 2016 Journal Article, 2016 DOI

Glenn Moynihan, Gilberto Teobaldi, and David D. O'Regan, Inapplicability of exact constraints and a minimal two-parameter generalization to the DFT+$U$ based correction of self-interaction error, Physical Review B, 94, (22), 2016, p220104(R) Journal Article, 2016 DOI

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

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

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 URL DOI

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

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

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., 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., 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 DOI URL

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., 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 URL DOI

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

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

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., 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

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., Geometric Aspects of Representation Optimisation, Optimised Projections for the Ab Initio Simulation of Large and Strongly Correlated Systems, 2012, p125-149 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 DOI URL

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