title: Real-space grids and the Octopus code as tools for the development of new simulation approaches for electronic systems.
abstract: Real-space grids are a powerful alternative for the simulation of electronic systems. One of the main advantages of the approach is the flexibility and simplicity of working directly in real space where the different fields are discretized on a grid, combined with competitive numerical performance and great potential for parallelization. These properties constitute a great advantage at the time of implementing and testing new physical models. Based on our experience with the Octopus code, in this article we discuss how the real-space approach has allowed for the recent development of new ideas for the simulation of electronic systems. Among these applications are approaches to calculate response properties, modeling of photoemission, optimal control of quantum systems, simulation of plasmonic systems, and the exact solution of the Schrödinger equation for low-dimensionality systems.
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, CA 94550, USA. xavier@tddft.org and Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA.
authors.forename: Xavier
authors.initials: X
authors.lastname: Andrade
authors.affiliation: Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: David
authors.initials: D
authors.lastname: Strubbe
authors.affiliation: Nano-Bio Spectroscopy Group and European Theoretical Spectroscopy Facility (ETSF), Universidad del País Vasco CFM CSIC-UPV/EHU-MPC & DIPC, 20018 Donostia-San Sebastián, Spain.
authors.forename: Umberto
authors.initials: U
authors.lastname: De Giovannini
authors.affiliation: Nano-Bio Spectroscopy Group and European Theoretical Spectroscopy Facility (ETSF), Universidad del País Vasco CFM CSIC-UPV/EHU-MPC & DIPC, 20018 Donostia-San Sebastián, Spain.
authors.forename: Ask Hjorth
authors.initials: AH
authors.lastname: Larsen
authors.affiliation: Unité Nanomat, Département de Physique, Université de Liège, Allée du 6 Août 17, B-4000 Liège, Belgium.
authors.forename: Micael J T
authors.initials: MJ
authors.lastname: Oliveira
authors.affiliation: Nano-Bio Spectroscopy Group and European Theoretical Spectroscopy Facility (ETSF), Universidad del País Vasco CFM CSIC-UPV/EHU-MPC & DIPC, 20018 Donostia-San Sebastián, Spain and Dept. of Computer Architecture and Technology, University of the Basque Country UPV/EHU, M. Lardizabal, 1, 20018 Donostia-San Sebastian, Spain.
authors.forename: Joseba
authors.initials: J
authors.lastname: Alberdi-Rodriguez
authors.affiliation: Nano-Bio Spectroscopy Group and European Theoretical Spectroscopy Facility (ETSF), Universidad del País Vasco CFM CSIC-UPV/EHU-MPC & DIPC, 20018 Donostia-San Sebastián, Spain.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Varas
authors.affiliation: Peter-Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich, D-52425 Jülich, Germany.
authors.forename: Iris
authors.initials: I
authors.lastname: Theophilou
authors.affiliation: Peter-Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich, D-52425 Jülich, Germany.
authors.forename: Nicole
authors.initials: N
authors.lastname: Helbig
authors.affiliation: Unité Nanomat, Département de Physique, Université de Liège, Allée du 6 Août 17, B-4000 Liège, Belgium.
authors.forename: Matthieu J
authors.initials: MJ
authors.lastname: Verstraete
authors.affiliation: Atomistic Simulation Centre, School of Mathematics and Physics, Queen's University Belfast, University Road, Belfast BT7 1NN, Northern Ireland, UK.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Stella
authors.affiliation: Center for Computational Physics, University of Coimbra, Rua Larga, 3004-516 Coimbra, Portugal.
authors.forename: Fernando
authors.initials: F
authors.lastname: Nogueira
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA.
authors.forename: Alán
authors.initials: A
authors.lastname: Aspuru-Guzik
authors.affiliation: Institute for Biocomputation and Physics of Complex Systems (BIFI) and Zaragoza Center for Advanced Modeling (ZCAM), University of Zaragoza, E-50009 Zaragoza, Spain and ARAID Foundation, María de Luna 11, Edificio CEEI Aragón, Zaragoza E-50018, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Castro
authors.affiliation: Institut für Physik, Martin-Luther-Universität Halle-Wittenberg, Von-Seckendorff-Platz 1, 06120 Halle (Saale), Germany.
authors.forename: Miguel A L
authors.initials: MA
authors.lastname: Marques
authors.affiliation: Nano-Bio Spectroscopy Group and European Theoretical Spectroscopy Facility (ETSF), Universidad del País Vasco CFM CSIC-UPV/EHU-MPC & DIPC, 20018 Donostia-San Sebastián, Spain and Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany.
authors.forename: Angel
authors.initials: A
authors.lastname: Rubio