Structure AuBes

Binary representatives of this structure are found among the Mn, Cr, Fe, Ru, Rh, Os monosilicides and germanides, Zr and Hf monoantimonides, AuBe and A1 (or Ga) compounds with Pd and Pt. Ternary phases such as CrMnSi2, CrFeSi2, CrCoSi2, FeMnSi2 have been described. 

Cu2Mg, cF24, structural type (and ordered derivatives cF24-CuJSIgSn and cF24-AuBes)... 

Substituted 6-aminohexanoic acid linkers were utilized by Aube et al.[159l to enforce either a type-I or type-II p-tum, depending on the substitutents at the R1 to R4 positions, in structure 119 (Scheme 43). 

The unit cell of LuMns is hexagonal, a = 5.186 and c = 8.566A with two molecules. The LuMns structure is related to that of MgZn2 as AuBes is related to MgCu2. The Mg sites of MgZn2 are occupied... 

Figure 2. The AuBe structure. The large open circles denote Au sites the dotted large circles and the small open circles denote Be sites (see also ref. 8). (Reproduced with permission from ref. 13. Copyright 1987 American Physical Society.)...

Fig. 2-20 The structure of AuBe, shared by FeSi, NiSi, CoSi, MnSi, etc. It is known as the FeSi structure [2.2].

These are the usual multiplicity factors. In some crystals, planes having these indices comprise two forms with the same spacing but different structure factor, and the multiplicity factor for each form is half the value given above. In the cubic system, for example, there are some crystals in which permutations of the indices (M/) produce planes which are not structurally equivalent in such crystals (AuBe, discussed in S. 2-7, is an example), the plane (123), for example, belongs to one form and has a certain structure factor, while the plane (321) belongs to another form and has a different structure factor. There are = 24 planes in the first form and 24 planes in the second. This question is discussed more fully by Henry, Lipson, and Wooster [G.8]. 

Study of the optical extinction spectra of the same two gold clusters, Aub and AU55, in solution leads to the same result with respect to the metal non-metal transition. The AU55 cluster core forms a metallic system characterized by collective excitation of the electrons. There is no indication of any molecular fine structure even at 2 K. The observed smearing of the band edge is responsible for damping... 

The geometries of the Aub-PVP and AUB-PVP4 models were also optimized, and their derived structures are displayed in Fig. 19.5. The calculated... 

Ali SM, Hoemann MZ, Aube J, Georg GI, Mitscher LA (1997) Butitaxel Analogues Synthesis and Structure-Activity Relationships. J Med Chem 40 236... 

In the near surface type, based on various engineered barriers (ENSF - Engineered Near Surface Facility), the disposal structures can be positioned above or below ground. The repository at Dukovany in Czech Republic, at I Aube in France and at El Cabril in Spain are above ground. The repositories at Drigg in the UK and at Rokkasho in Japan are below ground. 

It is assumed that the disposal structure is similar to the French one at L Aube or to the Spanish one in El Cabril. The waste is assumed to comply with the ANPA Technical Guide No. 26 (ANPA, 1985) and is, therefore, conditioned in a concrete matrix with compression strength of at least 500 000 kg m . ... 

Intramolecular variants are the most common type of Diels-Alder reactions employed in total syntheses with carbocycles the most popular targets. Among the broad variety of structures in this class, bicyclic decalin structures, both cis and trans, are readily available on intramolecular Diels-Alder reactions. Aube demonstrated the use of a tandem intramolecular Diels-Alder/Schmidt reaction sequence in his synthesis of three stemona alkaloids. The first steps generates cw-decalin intermediate 124, which undergoes a ring expansion in the Schmidt reaction to furnish tricycle 125. ° ... 

AnXs Stoichiometry AuBes-- and CaCus-type structures are found. 

The MgCotSn structure is the superstructure to the AuBes type, which is the derivative from the MgCu2 type. Only one stannide, LuNi4Sn, is known to crystallize in this structure type. 

Figure 135 shows the relative change in the lattice constant a/uo as a function of pressure at room temperature, where a and Oq are the lattice constants at high and ambient pressure, respectively. Since there are no new Bragg peaks up to 13 GPa, the AuBes structure is stable at room temperature at least to 13 GPa. A discontinuous change in the value of fl/flo, to be caused by the y-oc transition in Ce metal (Franceschi and Olcese, 1969), is not observed in the present pressure range within experimental error. This result indicates that a discontinuous valence transition as observed at Tv is not induced by pressure up to 13 GPa at room... 

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