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用自旋极化的MS－Xa方法计算了Nd_2Fe_(17)Nx（x=0,3)化合物中含哑铃Fe原子对的Fe8及合Nd原子的NdFe_6。原子簇的电子结构和磁矩．计算结果显示，Nd_2Fe_(17)化合物内在Fe（c）和Fe（f）间的分子轨道中，有三个奇宇称轨道呈现负交换耦合。通过比较a－Fe的MS－Xa计算结果，能够很好地说明R_2Fe_(17)化合物居里温度较低的原因。在化合物Nd_2Fe_(17)N_3中Fe（c）－Fe（f）间分子轨道只剩下一个奇宇称轨道呈现弱的负交换耦合，通过比较N_2Fe_(17)，与N_2Fe_(17)N_3化合物Fe_8原子簇的计算结足，能够很好地说明间隙原子M（=N、H或C）对R_2Fe_(17)M化合物居里温度产生影响的物理机理。对R_2Fe_(17)型化合物中影响Fe-Fe交换作用大小的主要因素，本文也作了讨论。
The spin-polarized MS-Xa method was used to calculate the NdFe_6 with dumbbell Fe atom pair and the NdFe_6 atom with Nd atom in the Nd_2Fe_ (17) Nx (x = 0,3) compounds. Electronic structure and magnetic moment of atomic clusters. The calculated results show that three odd-parity orbitals exhibit negative exchange coupling in the molecular orbital between Fe (c) and Fe (f) in Nd 2 Fe 17 compounds. By comparing the MS-Xa results of a-Fe, we can well explain why the Curie temperature of R 2 Fe 17 compounds is low. Only one odd-parity orbit exists in the molecular orbital of Fe (c) -Fe (f) in the Nd 2 Fe 17 N 3 compound, which shows weak negative exchange coupling. By comparing N 2 Fe 17 with N 2 Fe 17 N 3 compound Fe 8 The calculation of atomic clusters is sufficient to explain the physical mechanism of the influence of interstitial atoms M (= N, H or C) on the Curie temperature of R 2 Fe 17 M compounds. The main factors affecting the size of Fe-Fe exchange in R 2 Fe 17 compounds are also discussed in this paper.