Erik Ingemar Tellgren
Researcher

Hylleraas Centre for Quantum Molecular Sciences
Norwegian version of this page
Room
V218
Username
Visiting address
Sem Sælands vei 26
0371 Oslo
Postal address
Postboks 1033
0315 Oslo
I am a researcher at CTCC. I have contributed to two quantum chemistry packages (DALTON and DIRAC), and am the main author of a third program (LONDON). LONDON was written from scratch and is a unique quantumchemical tool to explore the effect of magnetic fields on molecules. Recently, I was awarded a research grant from the Norwegian Research Council to study molecular spin frustration due to relativistic effects and nonuniform magnetic fields.
My other research interests include:
 Molecules in strong magnetic fields: Quantum chemical work has almost exclusively focused on weak magnetic fields, the effect of which can be modelled as slight perturbations to molecules. By directly modelling the magnetic field effects without recourse to perturbation theory, my research has resulted in novel computational techniques with different strengths and weaknesses. A strength is the ability to explore the exotic physics and chemistry of molecules subject to magnetic field strengths several stronger than what can be produced in a laboratory.
 Development of CurrentDensity Functional Theory (CDFT): The most wellknown form of Density Functional Theory is only valid in the absence of external magnetic fields. When magnetic vector potentials are placed on an equal footing with scalar potentials, one should also place the current density on an equal footing with the density. The resulting framework, CDFT, is much less developed in terms of practical approximations than DFT, and it remains an interesting challenge to incorporate currentdependence in practical functionals.
 Formal aspects of DFT/CDFT: My research has helped understand some mathematical aspects of CDFT, such as the extension of Lieb's formulation of DFT to CDFT, the characterization of the class of current densities that can arise from valid quantum mechanical states (a version of the Nrepresentability problem), the status of the HohenbergKohnlike results in CDFT, etc.
 Linearscaling methods and PBC: Techniques for reducing the computational cost of SCF calculations on large systems as well as Periodic Boundary Conditions formulated using localized basis functions were among my first research projects. These themes have been not been the primary focus of recent research, but remain among my longterm interests.
Publications

Culpitt, Tanner Phillip; Peters, Laurens; Tellgren, Erik Ingemar & Helgaker, Trygve (2022). Analytic calculation of the Berry curvature and diagonal BornOppenheimer correction for molecular systems in uniform magnetic fields. Journal of Chemical Physics. ISSN 00219606. 156(4). doi: 10.1063/5.0079304.

Laestadius, Andre; Penz, Markus & Tellgren, Erik Ingemar (2021). Revisiting densityfunctional theory of the total current density. Journal of Physics: Condensed Matter. ISSN 09538984. 33(29). doi: 10.1088/1361648X/abf784. Full text in Research Archive

Kvaal, Simen; Laestadius, Andre; Tellgren, Erik Ingemar & Helgaker, Trygve (2021). Lower Semicontinuity of the Universal Functional in Paramagnetic CurrentDensity Functional Theory. The Journal of Physical Chemistry Letters. ISSN 19487185. 12(5), p. 1421–1425. doi: 10.1021/acs.jpclett.0c03422. Full text in Research Archive

Peters, Laurens; Culpitt, Tanner Phillip; Monzel, Laurenz; Tellgren, Erik Ingemar & Helgaker, Trygve (2021). Ab Initio molecular dynamics with screened Lorentz forces. II. Efficient propagators and rovibrational spectra in strong magnetic fields. Journal of Chemical Physics. ISSN 00219606. 155. doi: 10.1063/5.0056235.

Culpitt, Tanner Phillip; Peters, Laurens; Tellgren, Erik Ingemar & Helgaker, Trygve (2021). Ab initio molecular dynamics with screened Lorentz forces. I. Calculation and atomic charge interpretation of Berry curvature . Journal of Chemical Physics. ISSN 00219606. 155(2). doi: 10.1063/5.0055388. Full text in Research Archive

Sen, Sangita & Tellgren, Erik (2021). Benchmarking Density Functional Approximations for Diamagnetic and Paramagnetic Molecules in Nonuniform Magnetic Fields. Journal of Chemical Theory and Computation. ISSN 15499618. doi: 10.1021/acs.jctc.0c01222. Full text in Research Archive

Austad, Jon; Borgoo, Alex; Tellgren, Erik & Helgaker, Trygve (2020). Bonding in the helium dimer in strong magnetic fields: The role of spin and angular momentum. Physical Chemistry, Chemical Physics  PCCP. ISSN 14639076. 22(41), p. 23502–23521. doi: 10.1039/d0cp03259j.

Adamowicz, Ludwik; Stanke, Monika; Tellgren, Erik & Helgaker, Trygve (2020). A quantummechanical nonBorn–Oppenheimer model of a molecule in a strong magnetic field. Chemical Physics Letters. ISSN 00092614. 761, p. 1–7. doi: 10.1016/j.cplett.2020.138041. Full text in Research Archive

Laestadius, Andre; Tellgren, Erik; Penz, Markus; Ruggenthaler, Michael; Kvaal, Simen & Helgaker, Trygve (2019). Kohn–Sham Theory with Paramagnetic Currents: Compatibility and Functional Differentiability. Journal of Chemical Theory and Computation. ISSN 15499618. 15(7), p. 4003–4020. doi: 10.1021/acs.jctc.9b00141.

Penz, Markus; Laestadius, Andre; Tellgren, Erik & Ruggenthaler, Michael (2019). Guaranteed Convergence of a Regularized KohnSham Iteration in Finite Dimensions. Physical Review Letters. ISSN 00319007. 123(3). doi: 10.1103/PhysRevLett.123.037401. Full text in Research Archive

Sen, Sangita; Lange, Kai Kaarvann & Tellgren, Erik (2019). Excited States of Molecules in Strong Uniform and Nonuniform Magnetic Fields. Journal of Chemical Theory and Computation. ISSN 15499618. 15(7), p. 3974–3990. doi: 10.1021/acs.jctc.9b00103.

Reimann, Sarah; Borgoo, Alex; Austad, Jon; Tellgren, Erik; Teale, Andrew Michael & Helgaker, Trygve (2019). Kohn–Sham energy decomposition for molecules in a magnetic field. Molecular Physics. ISSN 00268976. 117(1), p. 97–109. doi: 10.1080/00268976.2018.1495849.

Adamowicz, Ludwik; Stanke, Monika; Tellgren, Erik & Helgaker, Trygve (2018). A computational quantummechanical model of a molecular magnetic trap. Journal of Chemical Physics. ISSN 00219606. 149(24), p. 2441121–24411211. doi: 10.1063/1.5055767.

Laestadius, Andre; Penz, Markus; Tellgren, Erik; Ruggenthaler, Michael; Kvaal, Simen & Helgaker, Trygve (2018). Generalized KohnSham iteration on Banach spaces. Journal of Chemical Physics. ISSN 00219606. 149(16), p. 1–9. doi: 10.1063/1.5037790. Full text in Research Archive

Sen, Sangita & Tellgren, Erik (2018). A local tensor that unifies kinetic energy density and vorticity in density functional theory. Journal of Chemical Physics. ISSN 00219606. 149(14), p. 1441091–14410910. doi: 10.1063/1.5041931. Full text in Research Archive

Sen, Sangita & Tellgren, Erik (2018). Nonperturbative calculation of orbital and spin effects in molecules subject to nonuniform magnetic fields. Journal of Chemical Physics. ISSN 00219606. 148(18). doi: 10.1063/1.5029431. Full text in Research Archive

Laestadius, Andre & Tellgren, Erik (2018). Densitywavefunction mapping in degenerate currentdensityfunctional theory. Physical Review A. Atomic, Molecular, and Optical Physics (PRA). ISSN 10502947. 97(2). doi: 10.1103/PhysRevA.97.022514. Full text in Research Archive

Tellgren, Erik (2018). Universal lower bounds on the kinetic energy of electronic systems with noncollinear magnetism. Physical Review A. Atomic, Molecular, and Optical Physics (PRA). ISSN 10502947. 97(2), p. 0225131–0225135. doi: 10.1103/PhysRevA.97.022513.

Tellgren, Erik; Laestadius, Andre; Helgaker, Trygve; Kvaal, Simen & Teale, Andrew Michael (2018). Uniform magnetic fields in densityfunctional theory. Journal of Chemical Physics. ISSN 00219606. 148(2), p. 1–19. doi: 10.1063/1.5007300.

Tellgren, Erik (2018). Densityfunctional theory for internal magnetic fields. Physical Review A. Atomic, Molecular, and Optical Physics (PRA). ISSN 10502947. 97(1), p. 1–17. doi: 10.1103/PhysRevA.97.012504.

Reimann, Sarah; Borgoo, Alex; Tellgren, Erik; Teale, Andrew Michael & Helgaker, Trygve (2017). MagneticField DensityFunctional Theory (BDFT): Lessons from the Adiabatic Connection. Journal of Chemical Theory and Computation. ISSN 15499618. 13(9), p. 4089–4100. doi: 10.1021/acs.jctc.7b00295. Full text in Research Archive

Adamowicz, Ludwik; Stanke, Monika; Tellgren, Erik & Helgaker, Trygve (2017). Explicitlycorrelated nonbornoppenheimer calculations of the HD molecule in a strong magnetic field. Chemical Physics Letters. ISSN 00092614. 682, p. 87–90. doi: 10.1016/j.cplett.2017.06.016.

Adamowicz, Ludwik; Tellgren, Erik & Helgaker, Trygve (2015). NonBornOppenheimer calculations of the HD molecule in a strong magnetic field. Chemical Physics Letters. ISSN 00092614. 639, p. 295–299. doi: 10.1016/j.cplett.2015.09.051.

Furness, James W.; Verbeke, Joachim; Tellgren, Erik; Stopkowicz, Stella; Ekström, Ulf Egil & Helgaker, Trygve [Show all 7 contributors for this article] (2015). Current density functional theory using metageneralized gradient exchangecorrelation functionals. Journal of Chemical Theory and Computation. ISSN 15499618. 11(9), p. 4169–4181. doi: 10.1021/acs.jctc.5b00535.

Stopkowicz, Stella; Gauss, Jürgen; Lange, Kai Kaarvann; Tellgren, Erik & Helgaker, Trygve (2015). Coupledcluster theory for atoms and molecules in strong magnetic fields. Journal of Chemical Physics. ISSN 00219606. 143:074110(7). doi: 10.1063/1.4928056.

Tellgren, Erik; Teale, Andrew Michael; Furness, J.W.; Lange, Kai Kaarvann; Ekström, Ulf Egil & Helgaker, Trygve (2014). Nonperturbative calculation of molecular magnetic properties within currentdensity functional theory. Journal of Chemical Physics. ISSN 00219606. 140(3). doi: 10.1063/1.4861427.

Tellgren, Erik; Kvaal, Simen & Helgaker, Trygve (2014). Fermion N representability for prescribed density and paramagnetic current density. Physical Review A. Atomic, Molecular, and Optical Physics (PRA). ISSN 10502947. 89(1). doi: 10.1103/PhysRevA.89.012515. Full text in Research Archive

Aidas, Kestutis; Angeli, Celestino; Bak, Keld L.; Bakken, Vebjørn; Bast, Radovan & Boman, Linus [Show all 83 contributors for this article] (2014). The Dalton quantum chemistry program system. Wiley Interdisciplinary Reviews. Computational Molecular Science. ISSN 17590876. 4(3), p. 269–284. doi: 10.1002/wcms.1172. Full text in Research Archive Show summary

Tellgren, Erik & Fliegl, Heike (2013). Nonperturbative treatment of molecules in linear magnetic fields: Calculation of anapole susceptibilities. Journal of Chemical Physics. ISSN 00219606. 139(16). doi: 10.1063/1.4826578.

Sagvolden, Espen; Ekström, Ulf Egil & Tellgren, Erik (2013). Isoorbital indicators for current density functional theory. Molecular Physics. ISSN 00268976. 111(911), p. 1295–1302. doi: 10.1080/00268976.2013.802383.

Tellgren, Erik; Reine, Simen Sommerfelt & Helgaker, Trygve (2012). Analytical GIAO and hybridbasis integral derivatives: application to geometry optimization of molecules in strong magnetic fields. Physical Chemistry, Chemical Physics  PCCP. ISSN 14639076. 14(26), p. 9492–9499. doi: 10.1039/c2cp40965h.

Kaarvann, Lange Kai; Tellgren, Erik; Hoffmann, Mark & Helgaker, Trygve (2012). A Paramagnetic Bonding Mechanism for Diatomics in Strong Magnetic Fields. Science. ISSN 00368075. 337(6092), p. 327–331. doi: 10.1126/science.1219703.

Tellgren, Erik; Kvaal, Simen; Sagvolden, Espen; Ekström, Ulf Egil; Teale, Andrew Michael & Helgaker, Trygve (2012). Choice of basic variables in currentdensityfunctional theory. Physical Review A. Atomic, Molecular, and Optical Physics (PRA). ISSN 10502947. 86(6). doi: 10.1103/PhysRevA.86.062506. Full text in Research Archive

Tellgren, Erik; Helgaker, Trygve & Soncini, Alessandro (2009). Nonperturbative magnetic phenomena in closedshell paramagnetic molecules. Physical Chemistry, Chemical Physics  PCCP. ISSN 14639076. 11(26), p. 5489–5498. doi: 10.1039/b822262b.

Tellgren , Erik I; Soncini, Alessandro & Helgaker, Trygve (2008). Nonperturbative ab initio calculations in strong magnetic fields using London orbitals. Journal of Chemical Physics. ISSN 00219606. 129, p. 1541141–1541149.

Reine, Simen Sommerfelt; Tellgren, Erik; Krapp, Andreas; Kjærgaard, Thomas; Helgaker, Trygve & Jansik, Branislav [Show all 8 contributors for this article] (2008). Variational and robust density fitting of fourcenter twoelectron integrals in local metrics. Journal of Chemical Physics. ISSN 00219606. 129(10). doi: 10.1063/1.2956507. Show summary

Salek, Pawel; Høst, Stinne; Thøgersen, Lea; Jørgensen, Poul; Manninen, Pekka & Olsen, Jeppe [Show all 12 contributors for this article] (2007). Linearscaling implementation of molecular electronic selfconsistent field theory. Journal of Chemical Physics. ISSN 00219606. 126.

Reine, Simen Sommerfelt; Tellgren, Erik & Helgaker, Trygve (2007). A unified scheme for the calculation of differentiated and undifferentiated molecular integrals over solidharmonic Gaussians. Physical Chemistry, Chemical Physics  PCCP. ISSN 14639076. 9, p. 4771–4779. doi: 10.1039/b705594c.

Peach, Michael J. G.; Tellgren, Erik; Salek, Pawel; Helgaker, Trygve & Tozer, David J. (2007). Structural and Electronic Properties of Polyacetylene and Polyyne from Hybrid and CoulombAttenuated Density Functionals. Journal of Physical Chemistry A. ISSN 10895639. 111, p. 11930–11935. doi: 10.1021/jp0754839.

Tellgren, Erik; Henriksson, J & Norman, P (2007). Firstorder excited state properties in the fourcomponent HartreeFock approximation: The excited state electric dipole moments in CsAg and CsAu. Journal of Chemical Physics. ISSN 00219606. 126.

Penz, Markus; Laestadius, Andre; Tellgren, Erik; Ruggenthaler, Michael & Lammert, Paul (2020). Erratum: Guaranteed Convergence of a Regularized KohnSham Iteration in Finite Dimensions. Physical Review Letters. ISSN 00319007. 125(24). doi: 10.1103/PhysRevLett.125.249902.

Tellgren, Erik & Helgaker, Trygve (2020). Strong Magnetic FieldInduced Chemical Bonding.

Laestadius, Andre; Penz, Markus; Tellgren, Erik; Ruggenthaler, Michael; Kvaal, Simen & Helgaker, Trygve (2019). Guaranteed convergence of a regularized KohnSham iteration in finite dimensions. Show summary

Tellgren, Erik; Helgaker, Trygve & Sen, Sangita (2019). Unifying kinetic energy density and current density in densityfunctional theory.

Tellgren, Erik; Helgaker, Trygve & Sen, Sangita (2019). Unifying kinetic energy density and current density in densityfunctional theory.

Tellgren, Erik; Helgaker, Trygve & Sen, Sangita (2019). Unifying kinetic energy density and current density in densityfunctional theory.

Helgaker, Trygve; Borgoo, Alex; Dimitrova, Maria; Gauss, Jurgen; Hampe, Florian & Holzer, Christof [Show all 13 contributors for this article] (2018). Diamagnetism and Paramagnetism in Atoms and Molecules.

Helgaker, Trygve; Borgoo, Alex; Gauss, Jurgen; Hampe, Florian; Klopper, Wim & Reimann, Sarah [Show all 9 contributors for this article] (2018). ClosedShell Molecular Paramagnetism.

Helgaker, Trygve; Borgoo, Alex; Gauss, Jurgen; Hampe, Florian; Klopper, Wim & Reimann, Sarah [Show all 9 contributors for this article] (2018). ClosedShell Molecular Paramagnetism.

Helgaker, Trygve; Borgoo, Alex; Gauss, Jurgen; Hampe, Florian; Klopper, Wim & Stopkowicz, Stella [Show all 8 contributors for this article] (2018). ClosedShell Molecular Magnetism.

Laestadius, Andre; Penz, Markus; Tellgren, Erik; Ruggenthaler, Michael; Kvaal, Simen & Helgaker, Trygve (2018). Generalized KohnSham iteration on Banach Spaces.

Sen, Sangita & Tellgren, Erik (2018). Excited Molecules in Strong Magnetic Fields.

Sen, Sangita & Tellgren, Erik (2018). A local tensor that unifies kinetic energy density and vorticity dependent exchangecorrelation functionals .

Sen, Sangita & Tellgren, Erik (2018). Molecules in Strong Magnetic Fields.

Sen, Sangita & Tellgren, Erik (2018). A local tensor that unifies kinetic energy density and vorticity dependent functionals in DFT.

Tellgren, Erik (2018). The HohenbergKohn theorem in a MaxwellSchrödinger setting.

Tellgren, Erik (2018). Magnetic fields, convexity and gauge invariance in density functional theory.

Tellgren, Erik; Lange, Kai Kaarvann; Sagvolden, Espen; Kvaal, Simen; Austad, Jon & Reimann, Sarah [Show all 9 contributors for this article] (2018). Quantum chemistry for strong magnetic fields.

Fliegl, Heike; Helgaker, Trygve & Tellgren, Erik (2018). The effect of strong magnetic fields on the ring currents of tetraoxaisophlorin.

Sen, Sangita & Tellgren, Erik (2017). Excited Molecules in Strong Magnetic Fields.

Tellgren, Erik (2017). Magnetic fields, convexity and gauge invariance in density functional theory.

Tellgren, Erik; Teale, Andrew Michael; Ekström, Ulf Egil; Kvaal, Simen; Sagvolden, Espen & Helgaker, Trygve (2015). Current density functional theory for molecular systems in strong magnetic fields.

Sagvolden, Espen; Tellgren, Erik; Ekström, Ulf Egil & Helgaker, Trygve (2014). Cusp based DFT functionals.

Teale, Andrew Michael; Furness, James; Tellgren, Erik; Ekström, Ulf Egil & Helgaker, Trygve (2014). Density Functional Theory for Molecules in Magnetic Fields.

Helgaker, Trygve; Borgoo, Alex; Ekström, Ulf Egil; Furness, James; Hoffmann, Mark & Kvaal, Simen [Show all 12 contributors for this article] (2014). DensityFunctional Theory in Magnetic Fields.

Helgaker, Trygve; Hoffmann, Mark; Lange, Kai Kaarvann; Soncini, Alessandro & Tellgren, Erik (2014). Molecules in Strong Magnetic Fields.

Sagvolden, Espen; Tellgren, Erik; Kvaal, Simen; Ekström, Ulf Egil; Teale, Andrew Michael & Helgaker, Trygve (2013). Building blocks of Current Density Functional Theory.

Sagvolden, Espen; Tellgren, Erik; Kvaal, Simen; Ekström, Ulf Egil; Teale, Andrew Michael & Helgaker, Trygve (2013). Building blocks of Current Density Functional Theory.

Ekström, Ulf Egil; Kvaal, Simen; Borgoo, Alex; Helgaker, Trygve; Sagvolden, Espen & Tellgren, Erik (2013). MoreauYosida regularization of DFT.

Kvaal, Simen; Ekström, Ulf Egil; Tellgren, Erik; Borgoo, Alex; Helgaker, Trygve & Sagvolden, Espen (2013). MoreauYosida regularization of DFT.

Helgaker, Trygve; Kaarvann, Lange Kai & Tellgren, Erik (2011). Molecules in strong magnetic fields. META. ISSN 18901956. p. 16–18.

Tellgren, Erik (2006). Implementation of Periodic Boundary Conditions in DALTON.

Tellgren, Erik (2006). Implementation of Periodic Boundary Conditions in DALTON.

Tellgren, Erik (2006). DesityFitting for the Coulomb interaction in periodic systems.

Tellgren, Erik & Helgaker, Trygve (2006). Introducing periodic boundary conditions into a molecular code.

Tellgren, Erik & Helgaker, Trygve (2006). Introducing periodic boundary conditions into a molecular code.

Austad, Jon; Helgaker, Trygve & Tellgren, Erik (2020). Theoretical Investigations of Molecular Electronic Structure in a Magnetic Field. Faculty of Mathematics and Natural Sciences, University of Oslo. ISSN 15017710. 2020(2295). Full text in Research Archive Show summary

Trøyflat, Jostein; Helgaker, Trygve; Tellgren, Erik & Reine, Simen Sommerfelt (2015). Efficient methods for selfconsistent field calculation of molecules in finite magnetic fields. Universitetet i Oslo.

Tellgren, Erik; Helgaker, Trygve; Ruud, Kenneth & Soncini, Alessandro (2009). Quantumchemical method development for extended and magnetic systems. Universitetet i Oslo.
Published Nov. 11, 2010 9:00 AM
 Last modified Sep. 29, 2020 2:53 PM