SrAu_4.76In_1.24 with YbMo₂Al₄-type structure

The gold-rich intermetallic compound SrAu4.76In1.24 was synthesized by high-frequence-melting of the elements in a sealed tantalum tube and subsequent annealing. The structure was refined from single-crystal X-ray diffraction data: YbMo2Al4-type, I4/mmm, Z = 2, a = 718.77(7), c = 552.79(9) pm, wR2 = 0.0760, 149 F2 values and 11 parameters. The 4d (0.62 In + 0.38 Au) Wyckoff position shows mixed occupancy leading to the composition SrAu4.76In1.24 for the investigated crystal. The strontium atoms are located in a large cage built up by 12 Au + 8 In atoms. The gold and indium atoms show segregation into substructures. The striking structural motifs are Au4 squares (278 pm Au-Au) and indium chains (276 pm In-In)..

SrAu_4.76In_1.24 with YbMo₂Al₄-type structure

The gold-rich intermetallic compound SrAu4.76In1.24 was synthesized by high-frequence-melting of the elements in a sealed tantalum tube and subsequent annealing. The structure was refined from single-crystal X-ray diffraction data: YbMo2Al4-type, I4/mmm, Z = 2, a = 718.77(7), c = 552.79(9) pm, wR2 = 0.0760, 149 F2 values and 11 parameters. The 4d (0.62 In + 0.38 Au) Wyckoff position shows mixed occupancy leading to the composition SrAu4.76In1.24 for the investigated crystal. The strontium atoms are located in a large cage built up by 12 Au + 8 In atoms. The gold and indium atoms show segregation into substructures. The striking structural motifs are Au4 squares (278 pm Au-Au) and indium chains (276 pm In-In)..

SrPt3In2 \u2013 an orthorhombically distorted coloring variant of SrIn5

The new intermetallic phase SrPt3In2 was synthesized by induction-melting of the elements in a sealed tantalum ampoule followed by long-term annealing for crystal growth. The SrPt3In2 structure was refined from single crystal X-ray diffraction data: Imma, a = 1674.7(6), b = 921.2(4), c = 971.2(4) pm, wR(2) = 0.0551, 1192 F-2 values and 55 variables. Electronic structure calculations indicate strong covalent Pt-In bonding and a substantial charge transfer from the strontium atoms to the three-dimensional [Pt3In2](delta-) polyanionic network. The strontium atoms fill larger cavities within the network and the bonding of strontium to the polyanion is of the electrostatic type. The Bader charge calculations classify SrPt3In2 as a ternary platinide. The close relationship between the SrPt3In2 structure and the aristotype CaCu5 is discussed on the basis of a group-subgroup scheme in the Barnighausen formalism along with other CaCu5 coloring variants and superstructures

A resource constraint approach for one global constraint MINLP

Many industrial optimization problems are sparse and can be formulated as block-separable mixed-integer nonlinear programming (MINLP) problems, where low-dimensional sub-problems are linked by a (linear) knapsack-like coupling constraint. This paper investigates exploiting this structure using decomposition and a resource constraint formulation of the problem. The idea is that one outer approximation master problem handles sub-problems that can be solved in parallel. The steps of the algorithm are illustrated with numerical examples which shows that convergence to the optimal solution requires a few steps of solving sub-problems in lower dimension