Refining to near spectroscopic accuracy the double many-body expansion potential energy surface for ground-state NH2

The single-sheeted double many-body expansion potential energy surface for the ground-state of NH2 is refined to attain near spectroscopic accuracy from a multiproperty fit to accurate ab initio energies and experimental vibrational levels, including the Renner–Teller effect for total angular momentum (excluding spin) of N = 0. Quasiclassical trajectory calculations on both the original and newly reported potential energy surfaces suggest that the dynamical properties of the original form remain essentially unaltered as aimed.