Figure 4.

a) Five descriptor families are obtained by factor analysis for 14 descriptors. Larger radial component indicates larger contribution of a descriptor to the factor. The factors can be considered as descriptor families, related to covalency (green), electrostatics (gray), structure (yellow), exchange interaction (red) and electron occupancy (dark gray). b) Heatmap of relative OER activity predictions for ABO₃ perovskites using the least angle regression model and data mined from the Materials Project database. Warmer colors indicate higher relative OER activity. Reproduced with permission.^{[ 22 ]} Copyright 2015, American Chemical Society.