◆1. Space attice 1 Definition Space lattice consists of an array of regularly arranged geometrical points called lattice points. The(periodic) arrangement of these points describes the regularity of the arrangement of atoms in crystals 2. Two basic features of lattice points O Periodicity: Arranged in a periodic pattern 2 Identity: The surroundings of each point in the lattice are identical◆ Ⅱ.Space lattice 1. Definition: Space lattice consists of an array of regularly arranged geometrical points, called lattice points. The (periodic) arrangement of these points describes the regularity of the arrangement of atoms in crystals. 2. Two basic features of lattice points ① Periodicity: Arranged in a periodic pattern. ② Identity: The surroundings of each point in the lattice are identical