Mendeleev

Mendeleev is used at run time in 10 crates. It is a direct run-time dependency in 3 crates.

Number of dependers	Mendeleev version	Downloads/month
7	0.8.4	600
3	0.7.0	0

Depender (with downloads and own rev deps)			Mendeleev version
250	2	numbat		^0.8.1
	1	minitpr		^0.8.0
	2	chem-eq		^0.7.0