Table 3.

T-test of distance between intra-cluster and inter-cluster compound structures gener-ated by atom-pair representation (α=0.01)

Target protein	H0	Average distance of intra-cluster compounds (Å)	Average distance of inter-cluster compounds (Å)	Stda of distance of intra-cluster compounds	Stda of distance of inter-cluster compounds	p-value
DHFR	Reject	0.42	0.63	0.15	0.12	5.84E-23
ESA	Reject	0.24	0.66	0.11	0.14	4.60E-65
EST	Reject	0.27	0.63	0.14	0.14	2.85E-56
NA	Reject	0.32	0.65	0.18	0.17	1.75E-131
TK	Reject	0.22	0.63	0.09	0.19	2.11E-93

^a Standard deviation