Born-Oppenheimer approximation

例句：

1. 1. The Born-Oppenheimer approximation is a method used to calculate the energy levels of atoms andmolecules in a quantum mechanical system.
   布隆-奥本海默近似是一种用于计算量子力学系统中原子和分子能量级的方法。
2. 2. In this approximation, the electrons are treated as point particles with zero mass.
   在这个近似中，电子被当作没有质量的点粒子来处理。
3. 3.The Born-Oppenheimer approximation is widely used in the field of quantum mechanics and has greatly improved our understanding of the behavior of atoms and molecules.
   布隆-奥本海默近似在量子力学领域得到了广泛应用，极大地提高了我们对原子和分子行为的理解。