Fig. 6
From: Machine learning of 27Al NMR electric field gradient tensors for crystalline structures from DFT
Illustration of the feature engineering process for element-specific features. A list of atomic properties for each atom within the first coordination shell was collected and then transferred into 3 sets of features: simple statistics of atomic properties, distance-normalized deviation of those atomic properties, and pairwise atomic properties matrices. * pc and pn are the atomic properties of the central atom, c, and coordinate atom, n; N is the coordination number; rcn is the corresponding bond length. †pn are the atomic properties of the atoms within the first coordination shell; rmn are the inter-atomic distances between atom m and atom n.
