应用群分解BHMO程序,研究了含S_2的固氮酶活性中心模型和N_2的络合活化模式.结果表明,在结构参数优化的情况下,平躺式络合与微斜插入式络合的键能差别不大(前者仅高约1ev),实际的络合方式很可能是直插式的或微斜插入式的,这样在加进1个H或两个H后,μ_3-H_2就转化为端基络合在Mo上的-N=NH或=N-NH_2。对奇数电子体系,由于其LUMO和NHOMO之间能级差别小,如对称性相同,易于产生d—d跃迁,从而为S=3/2的实验事实提供了可能的解释. The group decomposition BHMO program was used to study the active center of nitrogenase-containing S 2 and N 2 complex activation mode. The results show that under the optimized structural parameters, The difference is not so big (the former is only about 1ev). The actual complexation method is likely to be in-line or micro-oblique insertion, so after adding 1 H or 2 H, μ_3-H_2 will be transformed into terminal Base-complexed on Mo -N = NH or = N-NH_2. For odd-numbered electronic systems, a possible explanation for the experimental fact of S = 3/2 is provided due to the small energy difference between LUMO and NHOMO and the same symmetry, which makes it easy to generate d-d transitions.