Unrestricted Hartree-Fock calculations for a cluster model of CoO

1979 ◽  
Vol 12 (19) ◽  
pp. 3913-3919 ◽  
Author(s):  
D L Klein ◽  
G T Surratt ◽  
A B Kunz
Keyword(s):  
Cluster Model ◽  
Hartree Fock

scholarly journals RELATIVE MOTION CORRECTION TO FISSION BARRIERS

2008 ◽  
Vol 17 (01) ◽  
pp. 151-159 ◽  
Author(s):  
J. SKALSKI
Keyword(s):  
Relative Motion ◽  
Cluster Model ◽  
Motion Correction ◽  
Mean Field Theory ◽  
Mean Field ◽  
Ternary Fission ◽  
Skyrme Interaction ◽  
Hartree Fock ◽  
Fission Barriers ◽  
The Mean

We discuss the effect of kinetic energy of the relative motion becoming spurious for separate fragments on the selfconsistent mean-field fission barriers. The treatment of the relative motion in the cluster model is contrasted with the necessity of a simpler and approximate approach in the mean-field theory. A scheme of the energy correction to the Hartree-Fock is proposed. The results obtained with the effective Skyrme interaction SLy 6 show that the correction, previously estimated as ~ 8 MeV in A = 70 - 100 nuclei, amounts to 4 MeV in the medium heavy nucleus 198 Hg and to null in 238 U . However, the corrected barrier implies a shorter fission half-life of the latter nucleus. The same effect is expected to lower barriers for multipartition (i.e. ternary fission, etc) and make hyperdeformed minima less stable.

Embedded Cluster Model: Application to Molecular Crystals

2003 ◽  
Vol 800 ◽  
Author(s):  
Maija M. Kuklja ◽  
Frank J. Zerilli ◽  
Peter Sushko
Keyword(s):  
Multiscale Modeling ◽  
Cluster Model ◽  
Molecular Crystals ◽  
Hydrostatic Compression ◽  
Structure And Properties ◽  
Cluster Approach ◽  
Model Application ◽  
Hartree Fock ◽  
Structure Calculations ◽  
Crystal Structure Calculations

ABSTRACTMultiscale modeling using an embedded cluster approach is presented and applied to study the structure and properties of molecular crystals. We discuss the results of hydrostatic compression modeling of 1,1-diamino-2,2-dinitroethylene obtained with the embedded cluster model and the Hartree-Fock method and compare these with the full periodic crystal structure calculations. Details of the electronic structure of the perfect, highly compressed material are discussed. The results demonstrate the applicability of the embedded cluster model. We show that the band gap of the perfect material is not sensitive to hydrostatic compression, but some changes induced by the pressure take place in the valence band.

Unrestricted Hartree-Fock calculations for a cluster model of NiO

1977 ◽  
Vol 23 (8) ◽  
pp. 555-558 ◽  
Author(s):  
G. Timothy Surratt ◽  
A. Barry Kunz
Keyword(s):  
Cluster Model ◽  
Hartree Fock

The Mechanism of Slow Component Suppression in Lanthanum Doped Barium Fluoride Crystal

1994 ◽  
Vol 348 ◽  
Author(s):  
Gu Mu ◽  
Chen Lingyan ◽  
Li Qing ◽  
Wang Liming ◽  
Xiang Kaihua
Keyword(s):  
Electronic Structures ◽  
Cluster Model ◽  
Local Density ◽  
Slow Component ◽  
Barium Fluoride ◽  
Molecular Cluster ◽  
Entire System ◽  
Scintillation Light ◽  
Hartree Fock ◽  
Self Consistent

ABSTRACTThe electronic structures of pure BaF2 crystal and lanthanum doped BaF2 crystal have been calculated in a self-consistent molecular-cluster model. The cluster is embedded in the crystal lattice and the entire system treatediteratively in the Hartree-Fock-Slater local-density theory. As lanthanum doped BaF2 is concerned, the obtained results revealed that the F1–i which is introduced by the lanthanum may contribute to the suppression ofthe slow component in the scintillation light of BaF2 crystal.

The cyclic cluster model at hartree-fock level

2014 ◽  
Vol 35 (11) ◽  
pp. 839-846
Author(s):  
Michael F. Peintinger ◽  
Thomas Bredow
Keyword(s):  
Cluster Model ◽  
Hartree Fock ◽  
Cyclic Cluster

Hyperfine Interactions on Magnetic Ions Nuclei in Titanates

2014 ◽  
Vol 215 ◽  
pp. 109-112
Author(s):  
Polina A. Agzamova ◽  
Yulia V. Leskova ◽  
Anatoliy E. Nikiforov
Keyword(s):  
Field Theory ◽  
Experimental Data ◽  
Cluster Model ◽  
Hyperfine Interactions ◽  
Cluster Approach ◽  
Crystal Field Theory ◽  
Hartree Fock ◽  
Magnetic Ions ◽  
Hyperfine Interaction Parameters ◽  
Better Than

The electric and magnetic hyperfine interaction parameters (υQ, η, Hc) on 47,49Ti nuclei in lanthanum and yttrium titanates were calculated in the cluster model by the unrestricted Hartree-Fock method. The calculation in the cluster approach describes the experimental data better than that in the frameworks of LDA and LDA+U model and modern crystal-field theory.

scholarly journals Structure of S=−2 Hypernuclei and Hyperon–Hyperon Interactions

2018 ◽  
Vol 68 (1) ◽  
pp. 131-159 ◽  
Author(s):  
Emiko Hiyama ◽  
Kazuma Nakazawa
Keyword(s):  
Ground State ◽  
Cluster Model ◽  
Recent Progress ◽  
Energy Levels ◽  
Mean Field ◽  
Energy Spectra ◽  
Hartree Fock ◽  
Relativistic Mean Field ◽  
Hida Event ◽  
Extract Information

We review recent progress in S=−2 hypernuclei such as double-Λ hypernuclei and Ξ hypernuclei, which are composed of a nucleus and one or two hyperons, such as a Λ or a Ξ particle. Through observations of [Formula: see text]He, such as the Nagara event, we obtain important information about the ΛΛ interaction. Using this information, we perform a four-body calculation of ααΛΛ for [Formula: see text]Be, which was observed at KEK as the Demachi–Yanagi event. We interpret this event as the [Formula: see text] excited state. We calculate energy levels of [Formula: see text]Be within the framework of an αα nΛΛ five-body cluster model, and then interpret the Hida event, which was observed at KEK as the ground state of [Formula: see text]Be. Motivated by observation of the Kiso event of [Formula: see text]C, by using the Skyrme–Hartree–Fock and relativistic mean-field frameworks, we calculate the energy spectra of this hypernucleus. We interpret this event as the 14N(g.s.)+Ξ−(0 p) state. Finally, we propose an experiment on [Formula: see text]H and [Formula: see text]Li to extract information about the spin- and isospin-averaged parts of the Ξ N interaction.

Hydrogen Molecule in Silicon Crystal

1997 ◽  
Vol 469 ◽  
Author(s):  
K. G. Nakamura ◽  
K. Ishioka ◽  
M. Kitajima ◽  
K. Murakami
Keyword(s):  
Ab Initio ◽  
Cluster Model ◽  
Vibrational Frequency ◽  
Reasonable Agreement ◽  
Hydrogen Molecule ◽  
Tetrahedral Site ◽  
Silicon Crystal ◽  
Hartree Fock ◽  
Calculated Vibrational Frequency

ABSTRACTAb initio Hartree-Fock calculations have been performed on a hydrogen molecule in silicon crystal using a cluster model of Si10H16. The hydrogen molecule is stable at a tetrahedral site of silicon. A calculated vibrational frequency of the hydrogen molecule is in reasonable agreement with the experimentally determined frequency of H2 in the silicon crystal.

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