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Table 3567a. Interplanar crystal spacing (d) of the seven crystal families.
Triclinic 

Monoclinic 

Trigonal 

Orthorhombic 

Tetragonal 

Hexagonal 

Cubic 

Table 3567b. Packing density in some crystal planes and their interplanar distances in particular crystal structures.
The radius of the HOLZ rings is given by the interception of the Ewald sphere with the allowed HOLZ spots of the reciprocal lattice. In practice, the radius of the HOLZ ring is a direct measure of the interplanar spacing of the crystal along the direction of the directly transmitted electron beam. And, the interplanar spacing of the crystal can be approximately given by,
H = 2L^{2}λ/r^{2}  [3567]
where,
L  The camera length,
λ  The wavelength of the electron beam,
r  The radius of the HOLZ rings.
