Neuromyths for educational research and the educational field

status: publishe

Quasi-Hamiltonian Model Spaces

Let $K$ be a simple and simply connected compact Lie group. We call a quasi-Hamiltonian $K$-manifold $M$ a quasi-Hamiltonian model space if it is multiplicity free and its moment map is surjective. We classify all quasi-Hamiltonian model spaces by identifying a certain lattice that uniquely determines the space.Comment: 28 page

A note on the lower bound for online strip packing

This note presents a lower bound of $3/2+\sqrt{33}/6 \approx 2.457$ on the competitive ratio for online strip packing. The instance construction we use to obtain the lower bound was first coined by Brown, Baker and Katseff (1980). Recently this instance construction is used to improve the lower bound in computer aided proofs. We derive the best possible lower bound that can be obtained with this instance construction

Electron correlation effects in cobalt fluorides CoFn

The molecular cobalt fluorides CoF2, CoF3 and CoF4 are studied and compared by employing different basis sets as well as Quantum Information Theory (QIT) to investigate their correlation effects. These prototypical monomers may be systematically extended in size yielding a novel quasi 1‐dimensional, strongly correlated model system consisting of cobalt atoms bridged by oxygen atoms and fluorine termination on both ends. Accurate correlation energies are obtained using Full Configuration Interaction (FCI) and Full Configuration Interaction Quantum Monte Carlo (FCIQMC) calculations and the results are compared to Coupled Cluster and Density Matrix Renormalization Group (DMRG) energies. The analysis indicates the cobalt atom requires a larger number of one‐electron basis functions than fluorine and the use of localized molecular orbitals may facilitate calculations for the extended systems

A Hartree-Fock ab initio band-structure calculation employing Wannier-type orbitals

An ab initio Wannier-function-based approach to electronic ground-state calculations for crystalline solids is outlined. In the framework of the linear combination of atomic orbitals method the infinite character of the solid is rigorously taken into account. The Hartree-Fock ground-state energy, cohesive energy, lattice constant and bulk modulus are calculated in a fully ab initio manner as it is demonstrated for sodium chloride, NaCl, using basis sets close to the Hartree-Fock limit. It is demonstrated that the Hartree-Fock band-structure can easily be recovered with the current approach and agrees with the one obtained from a more conventional Bloch-orbital-based calculation. It is argued that the advantage of the present approach lies in its capability to include electron correlation effects for crystalline insulators by means of well-established quantum chemical procedures.Comment: 15 Pages, LaTex, 1 postscript figure (included), to appear in Chem. Phys. Letters (1998