Crystal Structure Flashcards
three-dimensional network of imaginary lines connecting the atoms
Space Lattice
the smallest unit having the full symmetry of the crystal
Unit Cell
three unequal axes, no two of which are perpendicular
Triclinic
three unequal axes, one of which is perpendicular to the other two
Monoclinic
three unequal axes, all perpendicular
Orthorhombic
three equal axes, not at right angles
Rhombohedral (trigonal)
three equal coplanar axes at 120 deg. and a fourth unequal axis perpendicular to their plane
Hexagonal
three perpendicular axes, only two equal
Tetragonal
three equal axes, mutually perpendicular
Cubic
If the atoms are represented as spheres, the center atom touches each corner atom but these do not touch each other
BCC
8 atoms at the corners x (1/8) = 1 atom
1 center atom = 1 atom
total = 2 atoms
BCC
In addition to an atom at each corner of the cube, there is one in the center of each face but none in the center of the cube.
FCC
8 atoms at the corners x (1/8) = 1 atom
6 face-centered atoms x (1/2) = 3 atoms
total = 4 atoms
FCC
Two basal planes in the form of regular hexagons with an atom at each corner of the hexagon and one atom at the center. Moreover, there are three atoms in the form of a triangle midway between between the two basal planes.
Close-packed Hexagonal
property of a material to exist in more than one type of space lattice in the solid state
Polymorphism
