对称,是生活中极为常见的一种现象。例如,很多建筑物的结构是左右对称的,化学工作者更熟悉许多物质如甲烷、苯分子等的分子结构具有各种不同的对称性。验证物质对称性的方法是对称操作。对一个分子而言,对称操作就是变换分子中各原子的位置,能得到与变换前一样的分子的操作。对称现象普遍存在于晶体 Symmetry is a very common phenomenon in life. For example, the structure of many buildings is bilaterally symmetrical, and chemists are more familiar with the many different symmetries in the molecular structure of many substances, such as methane and benzene molecules. The way to verify material symmetry is symmetry. For a molecule, the symmetry operation is to change the position of each atom in the molecule, and to obtain the same operation as before the transformation. Symmetry is common in crystals