Tetrahedral Sites in Cubic Cell
I am having trouble with the whole problem. Calculating the distance between tetrahedral sites and drawing the unit cell and whether the tetrahedra share vertices, edges or faces.
The actual problem is attached.
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Solution Summary
This solution provides a detailed explanation about tetrahedral sites in a cubic cell. The solution includes calculations of distances the tetrahedral sites, pictures of unit cells and tetrahedral sites, and description of vertices, edges, and faces on the sites.
Simple Solids - Structures
1. Draw one layer of close-packed spheres. On this layer mark the positions of the centers of the B layer atoms using the symbol X and, with the symbol O mark the positions of the centers of the C layer atoms of an fcc lattice.
2. Consider the structure of rock salt. (a) What are the coordination numbers of the anion and cation? (b) How many Na+ ions occupy second-nearest neighbor locations of an Na+ ion? (c) Pick out the closest-packed plane of CI- ions. (Hint: this hexagonal plane will be perpendicular to a threefold axis).
3. Consider the structure of cesium chloride. (a) What is the coordination number of the anion and cation? (b) How many Cs+ ions occupy second-nearest neighbor locations of a Cs+ ion?
4. (a) How many Cs+ ions and how many CI- ions are in the CsCI unit cell? (b) How many Zn2+ ions and how many S2- ions are in the sphalerite unit cell?
5. Given the following data for the length of a side of the unit cell for compounds "that crystallize in the rock-salt structure, determine the cation radii: MgSe (5.45 A). CaSe (5.91A). SrSe (6.23 A), BaSe (6.62 A.). (To determine the Se2- radius, assume that the Se2- ions are in contact in MgSe).
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