Interactive Tutorial about Diffraction
Interactive example: 2D crystal builder

Reciprocal space
Square lattice
Rectangular lattice
Oblique lattice
Translation of lattice
Rotation lattice

Interactive examples
2D crystal builder
Planes and HKL's
Finite size effect


The controls on the left allow you to create a grid of atoms (Pb). You can set the number of atoms in a- and b-direction, the ratio of the separation distance and angle between the axes. This defines the structure which than can be shifted and rotated with respect to the real space coordinate system. The X-ray diffraction pattern of the resulting structure is calculated.

Start exploring and try to answer the question below:

  • What is the relation ship between the axes defining the grid in real space and the axes defining a corresponding grid in the scattering pattern (reciprocal space) ?

  • What is the effect on the scattering intensity as you increase the number of atoms ?

  • How does rotating and shifting the complete structure change the diffraction pattern ?

The program will draw the crystal structure in the left image, and the corresponding diffraction pattern in the right image. All atoms will be drawn in blue, except the atom at the origin of the unit cell which is green. The unit cell is outlined in red. The corresponding unit cell in reciprocal space is drawn in blue.

Once you are done, click here to verify your answers.

© Th. Proffen and R.B. Neder, 2003