**Physics-432**

**Homework Set (1)**

This homework set is due on Sunday
(20^{th} Dhil-Qi'dah) at 10.00 p.m. If you need help, please
e-mail (or call) me. In __all__ homeworks, please solve fully and clearly,
state assumptions, circle final answers, and comment wisely (when applicable).
You are free to discuss with your colleagues, but makes sure your solution is
truly *yours*.

**Question #1:**

e-mail me[1] a Word Document attachment containing links to web-sites that describe each of the following:

- Bravais Lattices, Reciprocal Lattice and/ or Wigner Seitz Cell.
- Symmetry Operations
- Bragg Condition and/ or x-Ray Diffraction

Note: the site should have physlets and/ or simulation.

**Question #2:**

Show that the inter-planar distance between neighboring (h,k,l) planes
is 2p/|**G**|, where **G** is a
vector in reciprocal lattice such that **G** = h **b _{1}** + k

How dos this simplify for the case of a simple cubic lattice of dimension "a"?

Find the bond angle in the diamond lattice.

**Question #4:**

Calculate the packing fraction of the (close-packed):

- simple cubic structure

- body centered cubic structure

- face centered cubic structure

- diamond structure