la1∙∆k = 2πυ1 a2∙∆k = 2πυ2
la3∙∆k = 2πυ3
l
Each of the above describes a cone in reciprocal space about the lattice vectors a1, a2, and a3.
nthe
υi are
integers
When a reciprocal lattice point intersects this cone the diffraction condition is met, this is generally called the Ewald sphere.