Randić Matrix
The Randić matrix A_Randic of a simple graph is a weighted adjacency matrix with weight f(d_i, d_j) = 1/sqrt(d_i d_j), where d_i are the vertex degrees of the graph. In other words, [A_Randic]_(i j) = {1/sqrt(d_i d_j) | for i, j adjacent 0 | otherwise auto right match .