Browsing Kjemisk institutt by Author "Laestadius, Andre"

Now showing items 1-19 of 19

  • Analysis of the Extended Coupled-Cluster Method in Quantum Chemistry 
    Laestadius, Andre; Kvaal, Simen (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    The mathematical foundation of the so-called extended coupled-cluster method for the solution of the many-fermion Schrödinger equation is here developed. We prove an existence and uniqueness result, both in the full ...
  • Analysis of the Tailored Coupled-Cluster Method in Quantum Chemistry 
    Faulstich, Fabian Maximilian; Laestadius, Andre; Legeza, Örs; Schneider, Reinhold; Kvaal, Simen (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    n quantum chemistry, one of the most important challenges is the static correlation problem when solving the electronic Schrödinger equation for molecules in the Born--Oppenheimer approximation. In this article, we analyze ...
  • Coupled-Cluster theory revisited Part I: Discretization 
    Csirik, Mihaly Andras; Laestadius, Andre (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    In a series of two articles, we propose a comprehensive mathematical framework for Coupled-Cluster-type methods. These methods aim at accurately solving the many-body Schrödinger equation. In this first part, we rigorously ...
  • Coupled-Cluster theory revisited Part II: Analysis of the single-reference Coupled-Cluster equations 
    Csirik, Mihaly Andras; Laestadius, Andre (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    In a series of two articles, we propose a comprehensive mathematical framework for Coupled-Cluster-type methods. In this second part, we analyze the nonlinear equations of the single-reference Coupled-Cluster method using ...
  • Density-potential inversion from Moreau-Yosida regularization 
    Penz, Markus; Csirik, Mihaly Andras; Laestadius, Andre (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    For a quantum-mechanical many-electron system, given a density, the Zhao–Morrison–Parr method allows to compute the effective potential that yields precisely that density. In this work, we demonstrate how this and similar ...
  • Density-wave-function mapping in degenerate current-density-functional theory 
    Laestadius, Andre; Tellgren, Erik (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    Coupled cluster (CC) methods are among the most accurate methods in quantum chemistry. However, the standard CC linear response formulation is not gauge invariant, resulting in errors when modelling properties like optical ...
  • DFT exchange: sharing perspectives on the workhorse of quantum chemistry and materials science 
    Teale, Andrew Michael; Helgaker, Trygve; Savin, Andreas; Adamo, Carlo; Aradi, Balint; Arbuznikov, Alexei V.; Ayers, Paul W.; Baerends, Evert Jan; Barone, Vincenzo; Calaminici, Patrizia; Cances, Eric; Carter, Emily A.; Chattaraj, Pratim Kumar; Chermette, Henry; Ciofini, Ilaria; Crawford, T. Daniel; de Proft, Frank; Dobson, John F.; Draxl, Claudia; Frauenheim, Thomas; Fromager, Emmanuel; Fuentealba, Patricio; Gagliardi, Laura; Galli, Giulia; Gao, Jaili; Geerlings, Paul; Gidopoulos, Nikitas I.; Gill, Peter M. W.; Gori-Giorgi, Paola; Görling, Andreas; Gould, Tim; Grimme, Stefan; Gritsenko, Oleg; Jensen, Hans Jørgen Aagaard; Johnson, Erin R.; Jones, Robert O.; Kaupp, Martin; Köster, Andreas M.; Kronik, Leeor; Krylov, Anna I.; Kvaal, Simen; Laestadius, Andre; Levy, Mel; Lewin, Mathieu; Liu, Shubin; Loos, Pierre-Francois; Maitra, Neepa T.; Neese, Frank; Perdew, John P.; Pernal, Katarzyna; Pernot, Pascal; Piecuch, Piotr; Rebolini, Elisa; Reining, Lucia; Romaniello, Pina; Ruzsinszky, Adrienn; Salahub, Dennis R.; Scheffler, Matthias; Schwerdtfeger, Peter; Staroverov, Viktor N.; Sun, Jianwei; Tellgren, Erik Ingemar; Tozer, David J.; Trickey, Samuel B.; Ullrich, Carsten A.; Vela, Alberto; Vignale, Giovanni; Wesolowski, Tomasz A.; Xu, Xin; Yang, Weitao (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
    In this paper, the history, present status, and future of density-functional theory (DFT) is informally reviewed and discussed by 70 workers in the field, including molecular scientists, materials scientists, method ...
  • Exchange-only virial relation from the adiabatic connection 
    Laestadius, Andre; Csirik, Mihaly Andras; Penz, Markus; Tancogne-Dejean, Nicolas; Ruggenthaler, Michael; Rubio, Angel; Helgaker, Trygve (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2024)
    The exchange-only virial relation due to Levy and Perdew is revisited. Invoking the adiabatic connection, we introduce the exchange energy in terms of the right-derivative of the universal density functional w.r.t. the ...
  • Generalized Kohn-Sham iteration on Banach spaces 
    Laestadius, Andre; Penz, Markus; Tellgren, Erik; Ruggenthaler, Michael; Kvaal, Simen; Helgaker, Trygve (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2018)
    A detailed account of the Kohn–Sham (KS) algorithm from quantum chemistry, formulated rigorously in the very general setting of convex analysis on Banach spaces, is given here. Starting from a Levy–Lieb-type functional, ...
  • Guaranteed convergence for a class of coupled-cluster methods based on Arponen's extended theory 
    Kvaal, Simen; Laestadius, Andre; Bodenstein, Tilmann (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
    A wide class of coupled-cluster methods is introduced, based on Arponen's extended coupled-cluster theory. This class of methods is formulated in terms of a coordinate transformation of the cluster operators. The mathematical ...
  • Guaranteed Convergence of a Regularized Kohn-Sham Iteration in Finite Dimensions 
    Penz, Markus; Laestadius, Andre; Tellgren, Erik; Ruggenthaler, Michael (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    The exact Kohn-Sham iteration of generalized density-functional theory in finite dimensions with a Moreau-Yosida regularized universal Lieb functional and an adaptive damping step is shown to converge to the correct ...
  • Lower Semicontinuity of the Universal Functional in Paramagnetic Current-Density Functional Theory 
    Kvaal, Simen; Laestadius, Andre; Tellgren, Erik Ingemar; Helgaker, Trygve (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
    A cornerstone of current–density functional theory (CDFT) in its paramagnetic formulation is proven. After a brief outline of the mathematical structure of CDFT, the lower semicontinuity and expectation-valuedness of the ...
  • One-dimensional Lieb–Oxford bounds 
    Laestadius, Andre; Faulstich, Fabian Maximilian (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2020)
    We investigate and prove Lieb–Oxford bounds in one dimension by studying convex potentials that approximate the ill-defined Coulomb potential. A Lieb–Oxford inequality establishes a bound of the indirect interaction energy ...
  • Revisiting density-functional theory of the total current density 
    Laestadius, Andre; Penz, Markus; Tellgren, Erik Ingemar (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
    Abstract Density-functional theory (DFT) requires an extra variable besides the electron density in order to properly incorporate magnetic-field effects. In a time-dependent setting, the gauge-invariant, total ...
  • The coupled-cluster formalism – a mathematical perspective 
    Laestadius, Andre; Faulstich, Fabian Maximilian (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    The Coupled-Cluster (CC) theory is one of the most successful high precision methods used to solve the stationary Schrödinger equation. In this article, we address the mathematical foundation of this theory with focus on ...
  • The S-diagnostic - an a posteriori error assessment for single-reference coupled-cluster methods 
    Faulstich, Fabian M.; Kristiansen, Håkon Emil; Csirik, Mihaly Andras; Kvaal, Simen; Pedersen, Thomas Bondo; Laestadius, Andre (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2023)
    We propose a novel a posteriori error assessment for the single-reference coupled-cluster (SRCC) method called the S-diagnostic. We provide a derivation of the S-diagnostic that is rooted in the mathematical analysis of ...
  • The structure of the density-potential mapping Part I: Standard density-functional theory 
    Penz, Markus; Tellgren, Erik Ingemar; Csirik, Mihaly Andras; Ruggenthaler, Michael; Laestadius, Andre (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    The Hohenberg–Kohn theorem of density-functional theory (DFT) is broadly considered the conceptual basis for a full characterization of an electronic system in its ground state by just the one-body particle density. Part ...
  • The Structure of the Density-Potential Mapping. Part II: Including Magnetic Fields 
    Penz, Markus; Tellgren, Erik Ingemar; Csirik, Mihaly Andras; Ruggenthaler, Michael; Laestadius, Andre (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    The Hohenberg–Kohn theorem of density-functional theory (DFT) is broadly considered the conceptual basis for a full characterization of an electronic system in its ground state by just one-body particle density. In this ...
  • Unique continuation for the magnetic Schrodinger equation 
    Laestadius, Andre; Benedicks, Michael; Penz, Markus (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
    The unique‐continuation property from sets of positive measure is here proven for the many‐body magnetic Schrödinger equation. This property guarantees that if a solution of the Schrödinger equation vanishes on a set of ...