The spectroscopic properties and anharmonic force fields of NaNH₂ are studied in present work by DFT (B3P86 and B3PW91) and MP2 methods in combination with 6-311++G(2d, 2p) and 6-311++G(3df, 2pd) basis sets. The calculated equilibrium geometry, ground state rotational constants and centrifugal distortion constants of NaNH₂ at B3P86/6-311++G(3df, 2pd) theoretical level agree very well with the corresponding experimental values. Noteworthy, some spectroscopic constants and anharmonic force fields of NaNH₂, which have not been experimentally measured, are firstly predicted. In addition, the spectroscopic properties of KNH₂ are also predicted at the B3P86/6-311++G(3df, 2pd) level of theory. The influences of metal atoms on the equilibrium geometry, anharmonic constants, rotational constants, centrifugal distortion constants of MNH₂ (M = Li, Na, K) are analyzed intuitively. One can find that the metal atoms affect the rotational constants, part of centrifugal distortion constants (D_K, D_JK, H_K, and H_KJ), M-N bond length and some anharmonic constants of MNH₂.

通过DFT（B3P86和B3PW91）和MP2方法结合6-311 ++ G（2d，2p）和6-311 ++ G（3df，2pd）的方法研究了NaNH ₂的光谱性质和非谐力场）基础集。在B3P86 / 6-311 ++ G（3df，2pd）理论水平上计算得到的NaNH _2的平衡几何构型，基态旋转常数和离心变形常数与相应的实验值非常吻合。值得注意的是，首先预测了尚未通过实验测量的NaNH _2的一些光谱常数和非谐力场。另外，KNH ₂的光谱性质也可以在B3P86 / 6-311 ++ G（3df，2pd）的理论水平上进行预测。直观地分析了金属原子对MNH ₂（M = Li，Na，K）的平衡几何形状，非谐常数，旋转常数，离心变形常数的影响。可以发现，金属原子影响旋转常数，部分离心畸变常数（D _K，D _JK，H _K和H _KJ），MN键长和MNH _2的一些非谐常数。