Table 2. GBM-Locfit model summaries.

Model	Rank	Descriptor	Underlying property	RI (%)
K	1	log(V)	volume per atom	46.6
	2	μ1(Rn)	row number	24.5
	3	Ec	cohesive energy	19.4
	4	μ−4(X)	electronegativity	9.5
G	1	Ec	cohesive energy	37.0
	2	log(V)	volume per atom	35.9
	3	μ−3(Rn)	row number	13.8
	4	μ4(X)	electronegativity	13.3

Descriptor rank and relative influence (RI) for our best four descriptor models for K and G. Composition descriptors are constructed as Hölder means to the power p, μ_p(x), of property x.