1	GUN	Guanine	1.000
2	8IG	8-iodo-guanine	0.917
3	9MG	9-methylguanine	0.917
4	A1LXN	2-azanyl-8-methyl-1,9-dihydropurin-6-one	0.917
5	ANG	8-aminoguanine	0.917
6	B55	2-amino-8-sulfanyl-1,9-dihydro-6h-purin-6-one	0.917
7	BRG	8-bromoguanine	0.917
8	MY6	2-amino-7-methyl-1,7-dihydro-6h-purin-6-one	0.917
9	OXG	8-oxoguanine	0.917
10	2BP	9h-purin-2-amine	0.909
11	HPA	Hypoxanthine	0.909
12	NDM	7,9-dimethylguanine	0.846
13	2ON	2-sulfanyl-1,9-dihydro-6h-purin-6-one	0.833
14	6AP	9h-purine-2,6-diamine	0.833
15	6GU	6-chloroguanine	0.833
16	7DG	7-deazaguanine	0.833
17	9DG	9-deazaguanine	0.833
18	9QC	5-azanyl-3,6-dihydro-[1,2,3]triazolo[4,5-D]pyrimidin-7-one	0.833
19	AZG	5-amino-1h-[1,2,3]triazolo[4,5-D]pyrimidin-7-ol	0.833
20	BOA	2-bromo-6-hydroxy-purine	0.833
21	DX4	2-amino-1,9-dihydro-6h-purine-6-thione	0.833
22	HH5	6-iodanyl-7~{H}-purin-2-amine	0.833
23	QY8	2-amino-3h,4h,7h-pyrrolo[2,3-D]pyrimidin-4-one	0.833
24	XAN	Xanthine	0.833
25	WUT	9~{H}-purine	0.818
26	29H	2-aminopyrimido[4,5-D]pyrimidin-4(3h)-one	0.769
27	5JL	2,8-dithioxo-1,2,3,7,8,9-hexahydro-6h-purin-6-one	0.769
28	5JQ	2-thioxo-2,3,7,9-tetrahydro-1h-purine-6,8-dione	0.769
29	6GO	6-O-methylguanine	0.769
30	8HX	8-hydroxy-3,9-dihydro-1h-purine-2,6-dione	0.769
31	8TX	8-thioxo-3,7,8,9-tetrahydro-1h-purine-2,6-dione	0.769
32	A1IBK	2-azanyl-8-methyl-3,7-dihydropurine-6-thione	0.769
33	FDB	2-amino-5-methyl-3h-pyrrolo[2,3-D]pyrimidin-4(7h)-one	0.769
34	I7U	3-methyl-7~{H}-purine-2,6-dione	0.769
35	MOG	5-amino-2-methyl-6h-oxazolo[5,4-D]pyrimidin-7-one	0.769
36	PE0	Pterine	0.769
37	QBK	5-azanyl-[1,3]thiazolo[5,4-D]pyrimidine-2,7-dione	0.769
38	T0A	5-deazatetrahydropterin	0.769
39	URC	Uric acid	0.769
40	W5M	9-methyl-9h-purine-2,6-diamine	0.769
41	6MP	6-methylpurine	0.750
42	7HX	7h-pyrrolo[2,3-D]pyrimidin-4-ol	0.750
43	9HX	9-deazahypoxanthine	0.750
44	ADE	Adenine	0.750
45	BP1	6-bromo-7h-purine	0.750
46	ES4	6-chloro-9h-purine	0.750
47	PM6	9h-purine-6-thiol	0.750
48	GSY	7-(2-hydroxyethyl)-8-mercaptoguanine	0.733
49	28Y	3h-imidazo[2,1-B]purin-4(5h)-one	0.714
50	37T	Theobromine	0.714
51	44V	(6s)-2-amino-6-methyl-5,6,7,8-tetrahydropteridin-4(3h)-one	0.714
52	44W	2-amino-6-methyl-7,8-dihydropteridin-4(3h)-one	0.714
53	7PD	2-aminopteridine-4,7(3h,8h)-dione	0.714
54	B60	2-amino-8-methyl-7,8-dihydropteridin-4(3h)-one	0.714
55	B62	(6r)-2-amino-6-methyl-5,6,7,8-tetrahydropteridin-4(3h)-one	0.714
56	GD1	2-amino-5-[(z)-iminomethyl]-3,7-dihydro-4h-pyrrolo[2,3-D]pyrimidin-4-one	0.714
57	HNG	2-amino-5-(aminomethyl)-1,7-dihydro-4h-pyrrolo[2,3-D]pyrimidin-4-one	0.714
58	JSO	2-azanyl-6-methyl-3~{H}-pteridin-4-one	0.714
59	MUA	9-methyl uric acid	0.714
60	PQ0	2-amino-4-oxo-4,7-dihydro-3h-pyrrolo[2,3-D]pyrimidine-5-carbonitrile	0.714
61	PRF	7-deaza-7-aminomethyl-guanine	0.714
62	TEP	Theophylline	0.714
63	UAN	9-methyl-2-(methylamino)-1h-purin-6-one	0.714
64	XHP	2-amino-6-methylidene-6,7-dihydropteridin-4(3h)-one	0.714
65	XTN	2-amino-1,5-dihydropteridine-4,6-dione	0.714