Fig. 4. Molecular electrostatic potential surfaces. From left to right and from top to bottom: adenine, guanine, cytosine, uracil, indole, benzene, phenol, and imidazole, as simplified representations of nucleotides, deoxynucleotides, and side chains of the aromatic amino acids studied herein. The value of the component of the quadrupole moment (in Buckinghams) perpendicular to the ring is shown.
