A crystalline solid is characterized by a unit cell containing an arrangement of atoms repeated indefinitely; noncrystalline or glassy solids do not have a unit cell.

• 晶状固体的区别特征是，它有一个单位晶格；这个单位晶格包含着无限重复着的原子排列。非晶体或象玻璃的固体没有这样的单位晶格（或晶胞).