用电子衍射法测定气态分子中原子间距和分子的空间结构,从三十年代起就开始研究。由于科技的进步,电子衍射技术不仅在精度、可靠性、快速化方面有很快的发展,而且研究对象也在不断扩大。除测定分子中原子核间距和分子的空间结构外,还可测定振动的平均振幅和非谐性常数;测定原子和分子中的电荷分布, The electron diffraction method for the determination of gaseous molecules in the atomic spacing and the molecular structure of the space from the thirties onwards began to study. Due to the progress of science and technology, electron diffraction has not only rapid development in the aspects of accuracy, reliability and rapidity, but also the research objects are also expanding. In addition to measuring the distance between nuclei in a molecule and the spatial structure of the molecule, the average amplitude and the anharmonicity of the vibration can be measured; the charge distributions in the atom and molecule can be determined,