internal symmetry group

例句：

1. 1.The symmetry of the internal structure is crucialfor the stability of the system.
   系统内部结构的对称性对于系统的稳定至关重要。
2. 2. Thesymmetry of the crystal structure is a keyfactor in determining its physical properties.
   晶体结构的对称性是决定其物理性质的关键因素。
3. 3. The symmetry of the molecular structure isclosely related to its chemical reactivity.
   分子结构的对称性与它的化学活性密切相关。