[en] This paper reports that the equilibrium structure of NH₂ has been optimized at the QCISD/6-311++G (3df, 3pd) level. The ground-state NH₂ has a bent (C_2v, X²B₁) structure with an angle of 103.0582°. The geometrical structure is in good agreement with the other calculational and experimental results. The harmonic frequencies and the force constants have also been calculated. Based on the group theory and the principle of microscopic reversibility, the dissociation limits of NH₂(C_2v, X²B₁) have been derived. The potential energy surface of NH₂(X²B₁) is reasonable. The contour lines are constructed, the structure and energy of NH₂ reappear on the potential energy surface