Table 3. GBM-Locfit prediction accuracy.

Model	Iteration Threshold	Prediction RMSE (log(GPa))	Percent of Predictions within Relative Error of
			5%	10%	20%	30%
K	99	0.0750	33.1	58.4	87.3	94.5
G	90	0.1378	13.6	28.8	53.0	73.0

Iteration threshold as determined by cross validation, prediction root mean squared error (RMSE), and percentage of predictions within 5, 10, 20, and 30 percent relative error per equation (5) for our best four descriptor models for K and G.