0000000000053730

AUTHOR

Thierry Leininger

showing 3 related works from this author

Coupled-Cluster study of ‘no-pair’ bonding in the tetrahedral Cu4 cluster

2011

Abstract Ab initio Coupled-Cluster calculations with single and double excitations and perturbative correction to the triple, CCSD(T), have been carried out for the high-spin electronic state, ( 5 A 2 ) , of the copper cluster Cu 4 in its tetrahedral arrangement. Like alkali metals clusters, tetrahedral Cu 4 presents a bound quintet state, i.e., a situation where all the valence electrons are unpaired. This rather exotic wavefunction, also known as no-pair bonding state, is examined in detail. The influence of the basis set is also analyzed, as well as the importance of the core correlation and the effect of the basis-set superposition errors.

010304 chemical physicsChemistryAb initioGeneral Physics and Astronomy010402 general chemistryAlkali metal01 natural sciences0104 chemical sciencesCoupled cluster0103 physical sciencesPhysics::Atomic and Molecular ClustersCluster (physics)Tetrahedron[CHIM]Chemical SciencesPhysics::Chemical PhysicsPhysical and Theoretical ChemistryAtomic physicsValence electronWave functionBasis setChemical Physics Letters
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Computing the position-spread tensor in the CAS-SCF formalism II: Spin partition

2016

Abstract The Spin-Partitioned (SP) Total Position-Spread (TPS) tensor provides finer insights that supplement the information conveyed in the Spin-Summed (SS) TPS. The calculation of the SP-TPS has been implemented in the MOLPRO code for CAS-SCF wavefunctions allowing the study of electron (de) localization in relatively large molecular systems where the FCI treatment is rather unfeasible. An illustrative example considering one-dimensional Be wires is given as an application of the formalism.

Physics010304 chemical physicsGeneral Physics and AstronomyElectronMolecular systems010402 general chemistryTotal position spread01 natural sciences0104 chemical sciences[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistryFormalism (philosophy of mathematics)Theoretical physics0103 physical sciencesPartition (number theory)Physical and Theoretical ChemistryWave functionComputingMilieux_MISCELLANEOUSChemical Physics Letters
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A Wigner molecule at extremely low densities: a numerically exact study

2019

In this work we investigate Wigner localization at very low densities by means of the exact diagonalization of the Hamiltonian. This yields numerically exact results. In particular, we study a quasi-one-dimensional system of two electrons that are confined to a ring by three-dimensional gaussians placed along the ring perimeter. To characterize the Wigner localization we study several appropriate observables, namely the two-body reduced density matrix, the localization tensor and the particle-hole entropy. We show that the localization tensor is the most promising quantity to study Wigner localization since it accurately captures the transition from the delocalized to the localized state an…

Physics010304 chemical physicsStrongly Correlated Electrons (cond-mat.str-el)PhysicsQC1-999FOS: Physical sciencesObservableElectron01 natural sciences[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistryDelocalized electronCondensed Matter - Strongly Correlated ElectronsExact resultsQuantum mechanics0103 physical sciencesMoleculeEntropy (information theory)Reduced density matrix[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat]010306 general physics
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