Gallium has an orthorhombic structure, with a0 0.45258 nm, b0 0.45186 nm and c0 = 0.76570 nm. The density is 5.904 g/cm3, and the atomic weigh is 69.72 g/mol. Determine: a- The number of atoms in each unit cell; b- The packing factor in the unit cell. %3D %3D %3D

Please draw and explain the formula units of the double perovskite structure of Cs2AgInCl6 per unit cell

Consider the two ceramic atomic packing arrangements shown in the Figure. The radius of the anion is RA=0.2 nm. At i) the smallest stable cation size in I) and ii) the largest stable cation radius in II), what are the radii of the cations? What are these arrangements called? Select one: 1) 2RA a. 1.00 RA, 0.155 RA; hexagonal, triangular O b. 0.225 RA, 0.732 RA; tetrahedral, octahedral OC. 0.155 RA, 0.414 RA; triangular and tetrahedral d. 0.225 RA, 0.732 RA: cubic, triangular II)

part 2  The structure of the unit cell when CaF2 crystallizes is shown below: What is the arrangement of the Ca2+ ions (white spheres)?   FCC   SC   HCP   BCC

a) A hexagonal close-packed layer in two dimensions is shown in figure 2.By identifying a suitable unit cell, calculate the packing fraction of this structure.

The unit cell of strontium titanate SrTiO3 is depicted on the left in the figure below showing the crystal structure as confirmed by X-ray diffraction experiments. The lattice constant is a - 3.9 × 10-¹0 m. A typical X-ray powder diffraction spectrum is displayed on the right. The wave length of the X-ray beam (Cu-Ka radiation) is λ = 1.54 × 10-¹⁰ m. Unit cell of SrTiO3; Sr atoms are shown in blue, Ti in black and the oxygen atoms are in red. Normalized intensity (a.u.) (001) 20 (011) 30 (III) 40 (200) (210) 50 (211) (220) (300) 60 20 (degrees) 70 (310) (311) >(222) (320) 80 90 (17) 100 X ray powder diffraction data for SrTiO3; the plot shows an overlay for two different SrTiO3 samples. [L. da Silva et al, J. Nanomat., doi:10.1155/2012/890397] a) Identify the Bravais lattice of SrTiO 3and specify the basis for the primitive unit cell shown in the figure. b) Explain how the Miller indices (hkl) describe a family of lattice planes. State a set of possible reciprocal lattice vectors. c)…

1/ What is meant by the term coordination number in the structure of a solid? 2/ How does the coordination number depend on the structure of the metal?