materials:
N2
H2
NH3
l
H2l
Hl
N2l
Nl
N2H2l
NHl
NH2l
NH3l
N2Hl
N2H4l
N4H2l

reaction:
R:N2,H2,H2,H2=NH3,NH3

elementary reactions:
1:H2,l=H2l
2:H2l,l=2 Hl
3:N2,l=N2l
4:N2l,l=2 Nl
5:N2l,H2l=N2H2l,l
6:N2H2l,l=2 NHl
7:Nl,Hl=NHl,l
8:NHl,Hl=NH2l,l
9:NHl,H2l=NH3l,l
10:NHl,Nl=N2Hl,l
11:NH2l,Hl=NH3l,l
12:NH2l,Nl=N2H2l,l
24:Hl,N2Hl=NH2l,Nl
25:NH3l=NH3,l