Perfect Crystals
In a crystal, the constitutive particles are arranged periodically, forming a lattice. In the following, we will consider that all particles are identical (so the above separation in factor and structure factors (3) holds). We also assume that all atoms have an identical environment (i.e. they form a Bravais lattice). The general case of lattice with a basis (see below) is not fundamentally different.
If the lattice is infinite and completely regular, the system is a perfect crystal. In addition, we will neglect all thermal motion, so that there is no need for averaging in (4). As in (2), we can write:
- .
The structure factor is simply the squared modulus of the Fourier transform of the lattice, and it is itself a periodic arrangement of points, known as the reciprocal lattice.
Read more about this topic: Structure Factor
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