2,319 research outputs found
Two- and Three-particle States in a Nonrelativistic Four-fermion Model in the Fine-tuning Renormalization Scheme. Goldstone mode "against" extension theory
In a nonrelativistic contact four-fermion model we show that simple
regularisation prescriptions together with a definite fine-tuning of the
cut-off-parameter dependence of ``bare'' quantities give the exact solutions
for the two-particle sector and Goldstone modes. Their correspondence with the
self-adjoint extension into Pontryagin space is established leading to
self-adjoint semi-bounded Hamiltonians in three-particle sectors as well.
Renormalized Faddeev equations for the bound states with Fredholm properties
are obtained and analysed.Comment: 23 pages, LaTeX, changed content, added references and two figures,
to appear in the Few Body System
Tris(tetrabutylammonium) hexakis(tert-butanethiolato-κS)hepta-μ3-chlorido-μ3-sulfido-hexamolybdate dihydrate
The octahedral cluster core of the anion in the structure of the title compound, (C16H36N)3[Mo6(C4H9S)6(μ3-Cl)7(μ3-S)]·2H2O, has -3 site symmetry. Two μ3-Cl atoms fully occupy positions in the cluster core, while the remaining six positions are statistically occupied by Cl and S atoms in a 1:5 ratio. The fully occupied Cl-atom positions are located on sites with 3 symmetry, and the N atom of tetrabutylammonium cation is located on a site with 2 symmetry. The structure contains also two disordered solvent water molecules, one of which is located on a threefold rotation axis and the other in a general position, both with an occupancy of 0.25. The water molecules are localized in cavities formed by the tetrabutylammonium cations and the tert-butanethiolate groups. The metal clusters are stacked in a cubic close packing arrangement along [001]
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