#P Becke3LYP/6-31G(d) scf=(tight) opt=(Z-Matrix,tight) 

Becke3LYP/6-31G(d) opt tight ammonia (C3v)  

0 1
X1
N2  1  1.0
H3  2  r3  1  a3
H4  2  r3  1  a3  3  +120.
H5  2  r3  1  a3  3  -120.

r3=1.01943508
a3=112.9696602