O=c1nc[nH][nH]c1=O    mol9001    0_1
O=c1nc[n-][nH]c1=O    mol9001    -1_1
O=c1nc[nH][n-]c1=O    mol9001    -1_2
O=c1nc[n-][n-]c1=O    mol9001    -2_1