Answer to Question #250540 in General Chemistry for chie

Question

Differentiate crystal structure, crystal system, and crystal form. 

Answer 1

A crystal structure is characterised by the positions of all the atoms in the unit cell, including the symmetry relations between atoms and the dimensions of the unit cell. (In three dimensions, the unit cell is the minimum volume delineated by three pairs of parallel planes which fully cover the space by three independent periodic translations.

There are nearly an infinite number of crystal structures

A crystal system is characterised by the symmetry properties of the crystal structure.

In three dimensions there are seven crystal systems:

Triclinic

Monoclinic

Orthorhombic

Tetragaonal

Trigonal

Hexagonal

Cubic