Binding energy score of the target compounds with SARS-CoV-2 RNA-dependent RNA polymerase (PDB ID: 6M71).

Compound	SARS-Cov-2 RNA-dependent RNA polymerase (PDB ID: 6M71)
	Affinity, kcal mol−1	Distance (in Å) from main residue		Functional group	Interaction
Penciclovir	−14.5929	2.63	Thr556	–NH2	H–donor
		2.71	Thr556	N of diazine	H–acceptor
		2.89	Arg553	Cyclic C O	H–acceptor
		2.14	Arg 555	Cyclic C O	H–acceptor
			Arg555	N of Diazole	H–acceptor
Ia	−14.0245	3.02	Thr556	Phenolic OH	H–donor
		2.99	Thr556	Phenolic OH	H–acceptor
		3.19	Cys622	Quinazoline ring	Pi–H
Ib	−13.8649	2.96	Thr556	Phenolic OH	H–donor
		2.70	Thr556	Phenolic OH	H–donor
		2.98	Arg553	Cyclic C O	H–acceptor
		2.98	Arg555	Cyclic C O	H–acceptor
Ic	−14.6145	2.93	Cys622	Cyclic C O	H–acceptor
		2.94	Asp452	phenolic OH	H–donor
		3.09	Lys621	Quinazoline ring	Pi–H
		3.17	Tyr619	Quinazoline ring	Pi–H
Id	−12.9652	2.81	Thr556	Phenolic OH	H–donor
		2.73	Lys621	Quinazoline ring	H–donor
		3.18	Asp618	–Cl	Halogen bond
Ic metabolite	−14.5929	3.71	Arg553	–Phenyl ring	Pi–cation
		3.61	Arg555	–Phenyl ring	Pi–cation