1	PRP	1-O-pyrophosphono-5-O-phosphono-alpha-D-ribofuranose	1.000
2	PCP	1-alpha-pyrophosphoryl-2-alpha,3-alpha-dihydroxy-4-beta-cyclopentane-methanol-5-phosphate	0.913
3	RI2	1,5-di-O-phosphono-alpha-D-ribofuranose	0.739