1.61: Lattice
A lattice in the vector space V n is the set of all integral linear combinations t = u 1 a 1 + u 2 a 2 + ... + u k a k of a system ( a 1 , a 2 , ... , a k ) of linearly independent vectors in V n .
If k = n , i.e. if the linearly independent system is a basis of V n , the lattice is often called a full lattice . In crystallography, lattices are almost always full lattices, therefore the attribute "full" is usually suppressed.