铍的天然同位素是9^Be，其优异的中子特性在核能领域具有重要应用价值。铍核外电子排布为1s^2 2s^2。铍作为碱土金属元素但是易形成共价化合物。其成键性质与低能2s^1 2p^1激发态密切相关，由于多组态和强电子相关效应，铍配位与成键的高精度理论计算仍存在很大挑战。本项目将利用激光溅射离子源产生系列铍团簇和含铍分子负离子，结合高分辨光电子速度成像谱仪测量含铍分子和团簇的电子结构，光电子成像同时还能得到脱附电子角分布信息，由于激光脱附过程涉及电子从分子的价键轨道移出，所以能直接探测铍2s或2p轨道参与化学成键的信息。精确的实验数据能够直接用于检验现有的铍理论计算方法，通过实验与理论对比进而在原子和分子水平上揭示铍配位结构和成键规律。

9^Be is the only nature occurring isotope for Beryllium. Because of its unique neutron character, 9^Be has very important application in nuclear energy industry. The electronic structure of Be is 1s^2 2s^2, although Be is alkaline earth metal, but its compound contain substantial covalence in chemical bonding. The bonding character correlate to its 2s^1 2p^1 excited state, due to multi-configuration and strong electron correlation effects, accurate ab initio calculation for Be bonding remain big challenge. This project will use laser ablation ion source to produce Be contained molecule and cluster anions, in which its electronic structure can be measured by photoelectron imaging system, and the photoelectron imaging of the detached electron contain angular distribution of certain valence molecular orbital, therefore, it can direct probing the Beryllium 2s and 2p participate chemical bonding. Furthermore, accurate experimental data provide test bed to verify theoretical method. The combination of experiment and theory can aid the understanding of Beryllium coordination chemistry and bonding.