Untitled Quiz

Study Notes

Crystal structure describes the ordered arrangement of atoms, ions or molecules in a crystalline material.
Crystallography is the experimental science of determining the arrangement of atoms in crystalline solids.
A crystalline solid is a solid material whose constituents are arranged in a highly ordered microscopic structure.
The smallest group of particles in the material that constitutes the repeating pattern is called the unit cell.
The unit cell completely defines the symmetry and structure of the entire crystal lattice, which is built up by repetitive translation of the unit cell along its principal axes.
The repeating patterns are said to be located at the points of the Bravais lattice.

Simple Cubic: 1 atom per unit cell; Packing Efficiency = 52.4%; Empty Space = 47.6%
Body-centered Cubic: 2 atoms per unit cell; Packing Efficiency = 68%; Empty Space = 32%
Face-centered Cubic: 4 atoms per unit cell; Packing Efficiency = 74%; Empty Space = 26%

Crystal defect: an imperfection in the regular geometrical arrangement of the atoms in a crystalline solid.
Defects can result from deformation of the solid, rapid cooling from high temperature, or high-energy radiation.
Defects influence the mechanical, electrical, and optical behavior of the solid.

Polymorphism: the ability of a solid material to exist in more than one form or crystal structure.
Polymorphism can be found in any crystalline material including polymers, minerals, and metals.
Examples include glycine, calcite, and aragonite.