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CI? In the unit cel 4. CsCI has a bcc structure. What is the coordination number

ID: 543294 • Letter: C

Question

CI? In the unit cel 4. CsCI has a bcc structure. What is the coordination number of Cs primitive or non-primitive? Justify your answer 5. Calculate the fraction of space that is occupied by packing spheres in the body-centered cubic structure to be 0.6802, or 68.2 % Show your work. 6. In the bcc structure atom A is at the center of the unit cell and has B atoms as nearest neighbors at the corners of the cell. The next nearest neighbors to A are sitting at the centers of the adjacent cells. How many such atoms are there? Are these A or B (see interpenetrating lattice model toward the end the second lecture). 7. It is possible to crystalize H2 in a cubic close packed lattice (fcc unit cell) having an edge length of 5.338 Å. Calculate the density of H2 in this.

Explanation / Answer

Q4.

if bcc structure,

then Cs is in the center, Cl in the edges / corner

therefore

the 2^3 = 8

for both species

coordination number = 8