11 citations · 20 across the 6 of their papers we have counts for
10 papers
A Conjecture on Antisymmetrized Geminal Power Wavefunctions
Patrick Cassam-Chenaï
We conjecture that ``Antisymmetrized Geminal Power'' wave functions, and, in particular, those of extreme type in Coleman's terminology (i.e. with all geminal coefficients equal),…
2D-Block Geminals: a non 1-orthogonal and non 0-seniority model with reduced computational complexity
Patrick Cassam-Chenaï, Thomas Perez, Davide Accomasso
We present a new geminal product wave function ansatz where the geminals are not constrained to be strongly orthogonal nor to be of seniority zero. Instead, we introduce weaker ort…
An improved lower bound for the maximal length of a multivector
Patrick Cassam-Chenaï
A new lower bound for the maximal length of a multivector is obtained. It is much closer to the best known upper bound than previously reported lower bound estimates. The maximal l…
Smeared Coulomb potential orbitals for the electron-nucleus mean field configuration interaction method
Patrick Cassam-Chenaï, Gilles Lebeau
We propose to use the eigenfunctions of a one-electron model Hamiltonian to perform electron-nucleus mean field configuration interaction (EN-MFCI) calculations. The potential ener…
Generalization of the concepts of seniority number and ionicity
Thomas Perez, Patrick Cassam-Chenaï
We present generalized versions of the concepts of seniority number and ionicity. These generalized numbers count respectively the partially occupied and fully occupied shells for…
Molien generating functions and integrity bases for the action of the SO(3) and O(3) groups on a set of vectors
Guillaume Dhont, Patrick Cassam-Chenaï, Frédéric Patras
The construction of integrity bases for invariant and covariant polynomials built from aset of three dimensional vectors under the SO(3) and O(3) symmetries is presented. Thispaper…
Spin contamination and noncollinearity in general complex Hartree-Fock wave functions
Patrick Cassam-Chenaï
An expression for the square of the spin operator expectation value, \textless{} S^2\textgreater{}, is obtained for a general complex Hartree-Fock (GCHF) wave function and decompos…
A Fast Algorithm for the Construction of Integrity Bases Associated to Symmetry-Adapted Polynomial Representations. Application to Tetrahedral XY4 Molecules
Patrick Cassam-Chenaï, Guillaume Dhont, Frédéric Patras
Invariant theory provides more efficient tools, such as Molien generating functions and integrity bases, than basic group theory, that relies on projector techniques for the constr…
Improving Guess Geminals for the Geminal Mean Field Configuration Interaction Method
Patrick Cassam-Chenaï, Giovanni Granucci
The purpose of this letter is to show that a rotation of Hartree-Fock canonical orbitals which minimizes the lowest eigenvalues of a configuration interaction calculation limited t…
Geometric Measure of Indistinguishability for Groups of Identical Particles
Patrick Cassam-Chenaï
The concept of p-orthogonality (1=< p =< n) between n-particle states is introduced. It generalizes common orthogonality, which is equivalent to n-orthogonality, and strong orthogo…