Effects of initial rotational quantum state excitations and thermal rate coefficient at room temperature for the $$\hbox {H}(^{2}\hbox {S}) + \hbox {NH}(\hbox {X}^{3}\Sigma ^{-}) \rightarrow \hbox {N}(^{4}\hbox {S}) + \hbox {H}_{2}(\hbox {X}^{1}\Sigma _{g}^{+})$$ H ( 2 S ) + NH ( X 3 Σ - ) → N ( 4 S ) + H 2 ( X 1 Σ g + ) reaction