Sc11Ir4, Sc11Os4, Sc11Ru4 and Zr11Os4 with a new cubic structure type described by means of a cluster concept

Abstract

Mg6Cu~6SivVI. All these crystal structures can be described geometrically by means of clusters similar to those found in ),-brass or Li22Si 5. Clusters here, however, are not isolated.

Crystal Chemistry of the New Families of Interstitial Compounds R6Mg23C (R = La, Ce, Pr, Nd, Sm, or Gd) and Ce6Mg23Z (Z = C, Si, Ge, Sn, Pb, P, As, or Sb)

“…The four Mn positions in Th 6 Mn 23 can in turn be occupied in an orderly fashion by two different species, and the cavity can be occupied by one of the already present elements (homostuffed case) or by a different one (heterostuffed). The following groups can be identified as in the scheme reported in Figure 1: (1) Th 6 Mn 23 -type binary compounds, (2) nonstuffed ternary compounds, with nonoccupied 4a cavities (Mg 6 Cu 16 Si 7 □ prototype, where Si occupies positions 24d and 4b), 6,7 (3) homostuffed binary compounds, with 4a cavities occupied by one of the two elements (Sc 22 Ir 8 ), 8,9 (4) heterostuffed ternary compounds, Th 6 Mn 23 derivatives with a third element in the 4a cavity (Zr 6 Zn 23 Si), 10 (5) homostuffed ternary compounds, like case 2 and with the 4a cavity filled by the elements either in 32f or 24d (Ti 6 M 7 Al 16 Al and Ti 6 Ni 16 Si 7 Si), 11 and (6) heterostuffed quaternary compounds, like case 2 and with a fourth element in 4a (U 6 Fe 16 Si 7 C). 12 Magnesium-based binary compounds crystallizing with the Th 6 Mn 23 type are known to exist only in combination with an alkaline earth metal (Sr or Ba) or with Th.…”

Crystal Structure and Chemical Bonding Analysis of BaPtCd2

“…The title compound, BaPtCd 2 was obtained from a stoichiometric mixture of the three elements. BaPtCd 2 represents the second compound described in the Ba‐Pt‐Cd system in addition to BaPt 2 Cd 4 4. It crystallizes in the orthorhombic space group Cmcm with three independent atomic position in the unit cell and is isotypic to the MgCuAl 2 ‐type structure10 (see Figure 1).…”

“…Recently, we have isolated BaPt 2 Cd 4 that contains chains of edge‐sharing Cd 4 tetrahedra bridged by four‐bonded Ba 3. With calcium, we have discovered the new compounds Ca 6 Pt 8 Cd 16 3 that is an ordered ternary variant of Sc 11 Ir 4 4 and Ca 6 PtCd 11 5 that presents a novel structure type. Ca 6 Pt 8 Cd 16 contains a 3D array of separate Cd 8 tetrahedral stars (TS) and a face‐centered cube of Pt@Ca 6 octahedra.…”

Crystal Chemistry of RE6MgxCd23–xPb [0.6(1) ≤ x ≤ 3.2(1); RE = La and Ce]. New Mixed‐Metal Derivatives of the RE6Cd23T Phases (T = Group 14/15/16 Element)

“…The large, highly symmetric cubic unit cell of Th 6 Mn 23 contains one Th site (Wyckoff position 24 e ) and four Mn sites (2 × 32 f , 24 d , and 4 a ). Since its discovery, the chemistry within this structure type has proven rich and varied, as shown in the wide array of binary, ternary, and quaternary derivatives that have been discovered so far . This structure type also features a sizeable void at Wyckoff position 4 a .…”

“…The compounds found within this structure type need not conserve the 6:23 stoichiometric ratio, and in fact, a wide array of unique chemical formulae are known (Table S1, Supporting Information) . Such diverse stoichiometries, e.g.…”