12 research outputs found
A self-consistent perturbative evaluation of ground state energies: application to cohesive energies of spin lattices
The work presents a simple formalism which proposes an estimate of the ground
state energy from a single reference function. It is based on a perturbative
expansion but leads to non linear coupled equations. It can be viewed as well
as a modified coupled cluster formulation. Applied to a series of spin lattices
governed by model Hamiltonians the method leads to simple analytic solutions.
The so-calculated cohesive energies are surprisingly accurate. Two examples
illustrate its applicability to locate phase transition.Comment: Accepted by Phys. Rev.
Why edge inversion? Theoretical characterization of the bonding in the transition states for inversion in F n NH(3−n) and FnPH(3−n) (n = 0–3)
The First Row Anomaly and Recoupled Pair Bonding in the Halides of the Late p-Block Elements
Potential energy surfaces of WC6 clusters in different spin states
Stochastic explorations of the structural possibilities of neutral WC6 clusters in several spin states lead to very rich and complex potential energy surfaces, with geometries quite different from those of pure carbon clusters at the PBE0/def2-TZVP level. The global minimum is predicted to be a triplet-state semicyclic C6 conformation having every carbon in direct coordination to the W atom. Interaction energies are comparable to those of C7 clusters, revealing very strong W–C bonding. Our results suggest that C–C interactions in the clusters should be considered as intermediate between single and double bonds