Nc1nc(N)c(N)c(N)n1    mol7518    0_1
Nc1nc([NH3+])nc(N)c1N    mol7518    1_1
Nc1nc(N)c([NH3+])c(N)n1    mol7518    1_2
Nc1nc(N)c(N)c(N)[nH+]1    mol7518    1_3
Nc1nc(N)c(N)c([NH3+])n1    mol7518    1_4