Interplanar spacing, cubic crystals

For a cubic crystal system with interplanar spacing of d,... 

The magnitude of the distance between two adjacent and parallel planes of atoms (i.e., the interplanar spacing d, ) is a function of the Miller indices (h, k, and Z) as well as the lattice parameter(s). For example, for crystal structures that have cubic symmetry. 

ConcBpt Check 3.3 For cubic crystals, as values of the planar indices h, k, and I increase, does the distance between adjacent and parallel planes (i.e., the interplanar spacing) increase or decrease Why ... 

Periods of lattices a, b, c together with angles a, y, plane indexes (/ , k, 1) and interplanar spacing d are bound by a so-called quadratic form. For the simplest case of a cubic crystal, the quadratic form is presented by the equation... 

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