148 citations · 729 across the 22 of their papers we have counts for
22 papers
Spin-Generator Coordinate Method for Electronic Structure
Amir Ayati, Hugh G. A. Burton, Patrick Bultinck +1
We present a new application of the Generator Coordinate Method (GCM) as an electronic structure method for strong electron correlation in molecular systems. We identify spin fluct…
Can the electron density be interpreted information-theoretically? A critical analysis using quantum information theory
Guillaume Acke, Daria Van Hende, Ruben Van der Stichelen +1
Many quantum chemical similarity measures have been derived and substantiated by applying concepts and quantities from information theory to the electron density. To justify the us…
Spin-constrained Hartree-Fock and the generator coordinate method for the 2-site Hubbard model
Stijn De Baerdemacker, Amir Ayati, Hugh G. A. Burton +3
We present a mathematical analysis of the spin-constrained Hartree-Fock solutions (CHF) of the 2-site Hubbard model. The analysis sheds light on the spin symmetry breaking process…
Near-exact treatment of seniority-zero ground and excited states with a Richardson-Gaudin mean-field
Charles-Émile Fecteau, Samuel Cloutier, Jean-David Moisset +4
Eigenvectors of the reduced Bardeen-Cooper-Schrieffer Hamiltonian, Richardson-Gaudin (RG) states, are used as a variational wavefunction Ansatz for strongly-correlated electronic s…
Richardson-Gaudin mean-field for strong correlation in quantum chemistry
P. A. Johnson, C. -É. Fecteau, F. Berthiaume +8
Ground state eigenvectors of the reduced Bardeen-Cooper-Schrieffer Hamiltonian are employed as a wavefunction ansatz to model strong electron correlation in quantum chemistry. This…
Method For Making 2-Electron Response Reduced Density Matrices Approximately N-representable
Caitlin Lanssens, Paul W. Ayers, Dimitri Van Neck +3
In methods like geminal-based approaches or coupled cluster that are solved using the projected Schrödinger equation, direct computation of the 2-electron reduced density matrix (2…
Maximum Probability Domains for Hubbard Models
Guillaume Acke, Stijn De Baerdemacker, Pieter W. Claeys +4
The theory of Maximum Probability Domains (MPDs) is formulated for the Hubbard model in terms of projection operators and generating functions for both exact eigenstates as well as…
Projected seniority-two orbital optimization of the Antisymmetric Product of one-reference orbital Geminal
Katharina Boguslawski, Paweł Tecmer, Peter A. Limacher +5
We present a new, non-variational orbital-optimization scheme for the Antisymmetric Product of one-reference orbital Geminal wave function. Our approach is motivated by the observa…
Efficient description of strongly correlated electrons with mean-field cost
Katharina Boguslawski, Paweł Tecmer, Paul W. Ayers +3
We present an efficient approach to the electron correlation problem that is well-suited for strongly interacting many-body systems, but requires only mean-field-like computational…
Aliovalent Doping of CeO: DFT-study of Oxidation State and Vacancy Effects
Danny E. P. Vanpoucke, Patrick Bultinck, Stefaan Cottenier +2
The modification of the properties of CeO through aliovalent doping are investigated within the \emph{ab-initio} density functional theory framework. Lattice parameters, dopant…
Tetravalent doping of CeO: The impact of valence electron character on group IV dopant influence
D. E. P. Vanpoucke, S. Cottenier, V. Van Speybroeck +2
Fluorite CeO doped with group IV elements is studied within the DFT and DFT+U framework. Concentration dependent formation energies are calculated for CeZO (Z=…
Reply to 'Comment on "Extending Hirshfeld-I to bulk and periodic materials" '
D. E. P. Vanpoucke, I. Van Driessche, P. Bultinck
The issues raised in the comment by T.A. Manz are addressed through the presentation of calculated atomic charges for NaF, NaCl, MgO, SrTiO and LaCeO, using our pre…
Extending Hirshfeld-I to bulk and periodic materials
D. E. P. Vanpoucke, P. Bultinck, I. Van Driessche
In this work, a method is described to extend the iterative Hirshfeld-I method, generally used for molecules, to periodic systems. The implementation makes use of precalculated pse…
Tuning of CeO buffer layers for coated superconductors through doping
Danny E. P. Vanpoucke, Stefaan Cottenier, Veronique Van Speybroeck +2
The appearance of microcracks in CeO buffer layers, as used in buffer layer architectures for coated superconductors, indicates the presence of stress between this buffer layer…
Fast density-matrix based partitioning of the energy over the atoms in a molecule consistent with the Hirshfeld-I partitioning of the electron density
Diederik Vanfleteren, Dieter Ghillemijn, Dimitri Van Neck +3
For the Hirshfeld-I atom-in-molecule model, associated single-atom energies and interaction energies at the Hartree-Fock level are determined efficiently in one-electron Hilbert sp…
Hilbert-space partitioning of the molecular one-electron density matrix with orthogonal projectors
Diederik Vanfleteren, Dimitri Van Neck, Patrick Bultinck +2
A double-atom partitioning of the molecular one-electron density matrix is used to describe atoms and bonds. All calculations are performed in Hilbert space. The concept of atomic…
Partitioning of the molecular density matrix over atoms and bonds
Diederik Vanfleteren, Dimitri Van Neck, Patrick Bultinck +2
A double-index atomic partitioning of the molecular first-order density matrix is proposed. Contributions diagonal in the atomic indices correspond to atomic density matrices, wher…
Exact Ionization Potentials from Wavefunction Asymptotics: The Extended Koopmans' Theorem, Revisited
Diederik Vanfleteren, Dimitri Van Neck, Paul W. Ayers +2
A simple explanation is given for the exactness of the extended Koopmans' theorem for computing the removal energy of any many-electron system to the lowest-energy ground state ion…
A primal-dual semidefinite programming algorithm tailored to the variational determination of the two-body density matrix
B. Verstichel, H. van Aggelen, D. Van Neck +2
The quantum many-body problem can be rephrased as a variational determination of the two-body reduced density matrix, subject to a set of N-representability constraints. The mathem…
Variational density matrix optimization using semidefinite programming
Brecht Verstichel, Helen van Aggelen, Dimitri Van Neck +2
We discuss how semidefinite programming can be used to determine the second-order density matrix directly through a variational optimization. We show how the problem of characteriz…
Subsystem constraints in variational second order density matrix optimization: curing the dissociative behavior
Brecht Verstichel, Helen van Aggelen, Dimitri Van Neck +2
A previous study of diatomic molecules revealed that variational second-order density matrix theory has serious problems in the dissociation limit when the N-representability is im…
Variational determination of the second-order density matrix for the isoelectronic series of beryllium, neon and silicon
Brecht Verstichel, Helen van Aggelen, Dimitri Van Neck +2
The isoelectronic series of Be, Ne and Si are investigated using a variational determination of the second-order density matrix. A semidefinite program was developed that exploits…