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Dr. Charles Patterson

Associate Professor (Physics)

1982 B.Sc. (Hons.) in Chemistry, University of Bristol. 1982-85 PhD in Chemistry, University of Cambridge. PhD topic: Reactions at single crystal surfaces. 1986-90 Postdoctoral Fellow, University of Pennsylvania. Research topics: Electron energy loss spectroscopy and X ray photoelectron spectroscopy. Ab initio computational studies of surfaces and clusters. 1987 Visiting researcher A.T. and T. Bell Laboratories, Murray Hill, New Jersey. Research topic: Low energy ion scattering from NiAl(110). 1990 Postdoctoral Research Fellow, Department of Physics, TCD. Ab initio computational studies of optical properties of semiconductor surfaces. 1991-04 Lecturer in Science of Materials, Department of Physics,TCD. Research Interests: Computational materials science. 1997-11 Director of Computational Physics Degree Course, TCD. 2004-current Senior Lecturer/Associate Professor, Department of Physics, TCD.
  Atomic and molecular physics   Computational Physics   Condensed matter, electronic, magnetic and superconductive properties   Condensed matter, optical and dielectric properties   Magnetism and spin electronics   Quantum chemistry   Quantum mechanics   Theory and computational physics
 Exciton Computer Code
 Surface and Interface Optics Calculations
 Charge and Orbital Order in Magnetite

Details Date
Board or Steering Group Member, Psi-k Network European Network funded by successive European Commission Human Capital and Mobility and two 5 year European Science Foundation grants. 1994 to 2016
Board Member, European Physical Society Computational Physics Group. 1997 to 2002
Details Date From Date To
American Physical Society
Institute of Physics
Arthur-Baidoo, E. and Danielson, J.R. and Surko, C.M. and Cassidy, J.P. and Gregg, S.K. and Hofierka, J. and Cunningham, B. and Patterson, C.H. and Green, D.G., Positron annihilation and binding in aromatic and other ring molecules, Physical Review A, 109, (6), 2024, Notes: [cited By 0], Journal Article, PUBLISHED  TARA - Full Text  DOI
Cassidy, J.P. and Hofierka, J. and Cunningham, B. and Rawlins, C.M. and Patterson, C.H. and Green, D.G., Many-body theory calculations of positron binding to halogenated hydrocarbons, Physical Review A, 109, (4), 2024, Notes: [cited By 1], Journal Article, PUBLISHED  DOI
Rawlins, C.M., Hofierka, J., Cunningham, B., Patterson, C.H., Green, D.G., Many-Body Theory Calculations of Positron Scattering and Annihilation in H2, N2, and CH4, Physical Review Letters, 130, (26), 2023, Journal Article, PUBLISHED  DOI
Sahoo, Smruti Ranjan, Patterson, Charles H., Spectroscopic Identification of the Charge Transfer State in Thiophene/Fullerene Heterojunctions: Electroabsorption Spectroscopy from GW/BSE Calculations, The Journal of Physical Chemistry C, 127, (32), 2023, p15928-15942 , Journal Article, PUBLISHED  TARA - Full Text  DOI
Rawlins, C.M. and Hofierka, J. and Cunningham, B. and Patterson, C.H. and Green, D.G., Many-Body Theory Calculations of Positron Scattering and Annihilation in H2, N2, and CH4, Physical Review Letters, 130, (26), 2023, Notes: [cited By 9], Journal Article, PUBLISHED  DOI
Chaudhuri, D. and Patterson, C.H., Reliable prediction of the singlet-triplet gap in TADF molecules with GW/BSE approach, 2022-September, 2022, pp85-86 , Notes: [cited By 0], Conference Paper, PUBLISHED  DOI
Chaudhuri, D. and Patterson, C.H., TDDFT versus GW/BSE Methods for Prediction of Light Absorption and Emission in a TADF Emitter, Journal of Physical Chemistry A, 126, (51), 2022, p9627-9643 , Notes: [cited By 0], Journal Article, PUBLISHED  DOI
Sahoo, S.R. and Patterson, C.H., Charge transfer excitons in π -stacked thiophene oligomers and P3[Alkyl]T crystals: CIS calculations and electroabsorption spectroscopy, Journal of Chemical Physics, 157, (7), 2022, Notes: [cited By 0], Journal Article, PUBLISHED  DOI
Hofierka, J. and Cunningham, B. and Rawlins, C.M. and Patterson, C.H. and Green, D.G., Many-body theory of positron binding to polyatomic molecules, Nature, 606, (7915), 2022, p688-693 , Notes: [cited By 7], Journal Article, PUBLISHED  DOI
C. H. Patterson, Density fitting in periodic systems: Application to TDHF in diamond and oxides, The Journal of Chemical Physics, 153, (6), 2020, p064107 , Journal Article, PUBLISHED

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Charles H. Patterson, Density fitting approach to many-body calculations, 24th ETSF Workshop on Electronic Excitations, Jena, Germany, 16 - 20 September 20, edited by Claudia Roedl , 2019, Notes: [No workshop proceedings published], Oral Presentation, PRESENTED
C. H. Patterson, 'EXCITON code', TCD, 2017, -, Notes: [Code allows excitation spectra of molecules, 2-D slabs and 3-D bulk crystals to be computed using a combination of self-consistent Hartree-Fock, GW approximation and Bethe-Salpeter Equation calculations. The code is written in a gaussian orbital basis. Exciton consists of about 50,000 lines of C++ and message passing interface (MPI) code. The code has not yet been published but may be released under an Open Source license in future. It has been in development since 2004.], Software, PRODUCED
C. H. Patterson, S. Banerjee, P. Kumar and J. F. McGilp, Au at the Si(111) surface: silicene and Au nanowires probed by optical spectroscopy, Collaborative Conference on 3D and Materials Research, Songdo Convensia, Incheon, S. Korea, 22nd June 2016, 2016, Oral Presentation, PRESENTED
P. Kumar and C. H. Patterson, Optical characterisation of native point defects in ZnO and TiO2, European materials Research Society Spring Meeting, Lille, France, 11th - 15th May 2015, 2015, Notes: [], Poster, PRESENTED
C. H. Patterson, The Irish Transition Year and TYPE, The Gangwon Education International Symposium 2014, Chuncheon, Gangwon, S. Korea, 28th November, 2014, Gangwon-do Provincial Office of Education, Invited Talk, PRESENTED
C. H. Patterson, Optical Spectroscopy of 1-D Nanostructures at Si(111) Surfaces, Group Seminar, Department of Physics, Yonsei University, Seoul, S. Korea, 25th November , 2014, Oral Presentation, PRESENTED
C. H. Patterson, Crystal structure, charge and orbital order in magnetite: a new perspective from DFT calculations, Group seminar, Korea Advanced Insitute for Science and Technology , 26th November, 2014, Oral Presentation, PRESENTED
E. Mehes and C. H. Patterson, Defect levels and optical spectra of the Si(001):a-SiO2 interface, Workshop on dielectrics in microelectronics, Kinsale, Co. Cork, Ireland, 9th - 11th June 2014, 2014, Notes: [], Poster, PRESENTED
C. H. Patterson, S. Banerjee, S. Jorgji, P. Kumar, J. F. McGilp, Optical Anisotropy Calculations on Semiconductor and Oxide Surfaces, 10th International Conference on Optics of Surfaces and Interfaces , Chemnitz, Germany, 8th - 13th September, 2013, Dietrich R. T. Zahn (Technische Universität Chemnitz) Friedhelm Bechstedt (Friedrich Schiller University Jena) Norbert Esser (Leibniz-Institut für Analytische Wissenschaften - ISAS e.V.) , Invited Talk, PRESENTED
C. H. Patterson, Dielectric properties of semiconductor surfaces, International workshop on computational materials design and engineering, IIT Jodhpur, India, February, 2013, Prof Ambesh Dixit, IIT Jodhpur, Invited Talk, PRESENTED


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Award Date
Fellow of TCD 2000
Electronic structure theory code development Optics of semiconductor surfaces and interfaces Computational materials science Many-body theory of electrons in solids Electronic structure of magnetic materials My research consists of developing and applying electronic structure methods to problems in molecular, condensed matter and materials physics. Electronic structure theory is now a relatively mature field and density functional theory codes are available for many applications. More accurate many body methods, based on electron Green's functions, and electron-hole polarization propagators yield the most accurate predictions of excited state properties (Excitons) of molecules and condensed matter. The Exciton code performs self-consistent field Hartree-Fock calculations as well as GW (Green's function) and Bethe-Salpeter Equation calculations. Electronic structure codes divide roughly into those which represent electron wave functions using plane waves and those which use local orbitals. The former are best suited to crystalline materials with limited numbers of atoms per unit cell, the latter have many advantages for molecules, especially large molecules and systems with little or no symmetry. Accurate electronic structure methods such as the GW Green's function method and Bethe-Salpeter Equation polarization propagator method have applications in optical excitations of biomolecules, photovoltaics and photocatalysts for light harvesting and chemical reaction promotion such as artificial photosynthesis. Development of the Exciton code was begun with two graduate students, Drs. Conor Hogan and Svjetlana Galamic-Mulaomerovic, over a decade ago. That first phase of code development was based on a plane wave representation of the Coulomb potential, which is straightforward to code. The original Exciton code resulted in two publications in Physical Review B in 2005. Based on experience gained in developing the first Exciton code, I began developing an entirely new version of the code during a sabbatical year spent at the Quantum Theory Project, University of Florida, hosted by Prof. Rodney Bartlett. The new code employs the Ewald representation of the Coulomb potential for periodic systems. It makes full use of point, layer or space group symmetries in real and reciprocal space as well as time-reversal symmetry in reciprocal space. Symmetry is also used to transform the Gaussian atomic orbital basis into a symmetry adapted basis, which results in block diagonalization of operators, a reduction of running time and increased accuracy of wave functions. The many-body part of the code relies on an approach called Density fitting, which greatly reduces the time required to calculate Coulomb integrals over molecular orbitals. Current applications of the self-consistent Hartree-Fock, GW and BSE modules in the code to moleclues and molecular complexes have been tested using up to 1800 basis functions in the wave function basis and 4500 basis functions in the density fitting basis. Future development of the code will include the capacity to perform GW and Bethe-Salpeter Equation calculations for crystalline systems. Applications where the code would have significant advantages over plane wave codes are metal organic framework (MOF) materials which have open structures. Exciton is developed in C++ and MPI and consists of around 50,000 lines of code. The current Exciton code is also interfaced to the Crystal code which allows it to perform single-particle optical excitations calculations using wave functions and energy band structures from Crystal. This part of Exciton led to 15 publications in the seven year period since 2010. This version of the code produced two publications in 2005.