where NA and NB are the number of reference molecules for atoms A and B, C6,ref AB (CNi A ,CNj B ) are precomputed dispersion coefficients for the reference molecules, and CNi A , CNj B are the coordination numbers of the atoms A and B in the corresponding reference molecules. The term Lij indicates how far coordination numbers for pair AB are from the corresponding reference point AiBj. The explicit formula for this term in the D3 scheme is: