molecular excitation

例句：

1. 1.The molecular structure of the compound is crucial for its stability.
   化合物的分子结构对其稳定性至关重要。
2. 2.The molecular model helps us understand the chemical reactions better.
   分子模型有助于我们更好地理解化学反应。
3. 3.Molecular biology is a field that studies the structure and function of biological molecules.
   分子生物学是一门研究生物分子的结构与功能的学科。