Structural information content index

Definition:

n_i - number of atoms in the ith class

n - the total number of atoms in the molecule

k – number of atomic layers in the coordination sphere around a given atom that are accounted for

Reference:

1. S.C. Basak, D. K. Harriss, V. R. Magnuson, J. Pharm. Sci., 1984, 73, 429.