(n) mod . We look into how the covalent radius acts as a damping factor for the asymptotic behavior r ij → 0 in the standard Coulombic interaction tensor T . We investigate the 0th, 1st, and 2nd order derivatives of T mod in the 1D case when we vary r ij . In our test, we use three covalent radii values of 0.1, 0.31, and 0.73 Å. The lowest value here is chosen as the limit case, approaching the 0 value, so being the closest to the unmodified interaction tensor T (n) , 0.31 and 0.73 Å are the covalent radii of hydrogen and oxygen atoms, respectively. The results for T (n) mod derivatives up to the second order are visualized in Fig. .