Now showing items 1-9 of 9

  • 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 ...
  • 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 ...
  • 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 ...
  • 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, ...
  • 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 ...
  • 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 ...
  • 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 ...
  • 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 ...
  • 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 ...