# Formula Bragg's Law Diffraction order    Wavelength    Lattice constant    Angle

## Diffraction order

Unit
An integer number ($$m$$ = 0,1,2, ...) indicating a multiple of the wavelength $$m \, \class{violet}{\lambda}$$ at which constructive interference occurs.

## Wavelength

Unit
The wavelength characterizes the energy of the monochromatic light used to irradiate the crystal under investigation at an angle. X-rays are used in the study of crystals so that the wavelength is short enough to be within the range of the lattice constant. Only in this case diffraction phenomena can be observed.

## Lattice constant

Unit
Distance between two adjacent lattice planes of the crystal.

## Angle

Unit
The angle between the incident X-ray beam and the grating plane.