Therefore negative and neutral regions in space, around a molecule are revealed. Display is usually by a contoured diagram or if on a computer then the electrostatic potential energy surface is usually represented as a 3-D mesh. This gives a good indication of electrophilic and nucleophilic sites. This method has been further developed into the electric field method where the electrostatic field derived from a potential is displayed as a vector which shows the path taken by a proton at that point. These electrostatic forces are orienting forces and possibly control the initial orientation of, for example, a drug in an enzyme.
Critical points can occur where the direction component of the field is nil.
These may act as pivot points for the reorientation of a molecule. Hydrophilic portions of a molecule are usually those containing hydrogen-bonding, polar or ionizable groups. Hydrophobic portions of a molecule are those that are primarily hydrocarbon. The nature of the different parts of the molecule can affect the overall molecular conformation especially with large molecules and the way in which one molecule interacts with another. In binding of one molecule to another it is hypothesized that the interaction of two hydrophobic groups contributes as much to the complexes stability as one hydrogen bond.