1. Crystallography

6. Matter Crystalline Amorphous Solid Liquid Gas

7. Crystal?

8. A 3D translationally periodic arrangement of atoms in space is called a crystal.

9. A two-dimensional periodic pattern by a Dutch artist M.C. Escher

10. Lattice?

11. A 3D translationally periodic arrangement of points in space is called a lattice.

12. A 3D translationally periodic arrangement of atoms Crystal A 3D translationally periodic arrangement of points Lattice

13. What is the relation between the two? Crystal = Lattice + Motif Motif or basis: an atom or a group of atoms associated with each lattice point

14. Crystal=lattice+basis Lattice: the underlying periodicity of the crystal, Basis: atom or group of atoms associated with each lattice points Lattice: how to repeat Motif: what to repeat

15. + Love Pattern Love Lattice + Heart =

17. Lattice Finite or infinite?

18. Primitive cell Primitive cell Nonprimitive cell

20. Lattice Parameters Lengths of the three sides of the parallelopiped : a, b and c. The three angles between the sides:  ,  , 

22. The six lattice parameters a , b , c ,  ,  ,  The cell of the lattice lattice crystal + Motif