• Coupled-Cluster theory revisited Part I: Discretization 

      Mihaly Andras, Csirik; Laestadius, Andre (ESAIM: Mathematical Modelling and Numerical Analysis (ESAIM: M2AN);, Peer reviewed; Journal article, 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 ...
    • Density-potential inversion from Moreau-Yosida regularization 

      Penz, Markus; Csirik, Mihaly Andras; Laestadius, Andre (Peer reviewed; Journal article, 2023)
    • Exchange energies with forces in density-functional theory 

      Tancogne-Dejean, Nicolas; Penz, Markus; Laestadius, Andre; Csirik, Mihaly Andras; Ruggenthaler, Michael; Rubio, Angel (Peer reviewed; Journal article, 2024)
      We propose exchanging the energy functionals in ground-state density-functional theory with physically equivalent exact force expressions as a new promising route toward approximations to the exchange–correlation potential ...
    • Homotopy continuation methods for coupled-cluster theory in quantum chemistry 

      Faulstich, Fabian M.; Laestadius, Andre (Molecular Physics;, Peer reviewed; Journal article, 2023)
      Homotopy methods have proven to be a powerful tool for understanding the multitude of solutions provided by the coupled-cluster polynomial equations. This endeavor has been pioneered by quantum chemists that have undertaken ...
    • 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 (Peer reviewed; Journal article, 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 (Peer reviewed; Journal article, 2023)
    • The Structure of the Density-Potential Mapping. Part II: Including Magnetic Fields 

      Penz, Markus; Tellgren, Erik Ingemar; Csirik, Mihaly Andras; Ruggenthaler, Michael; Laestadius, Andre (Peer reviewed; Journal article, 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 ...
    • The Structure of the Density-Potential Mapping. Part II: Including Magnetic Fields 

      Penz, Markus; Tellgren, Erik Ingemar; Csirik, Mihaly Andras; Ruggenthaler, Michael; Laestadius, Andre (Peer reviewed; Journal article, 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 ...