Formation of dusty plasma molecules

The electrostatic interaction potential energy for two Debye shielded macroscopic grains or impurities is obtained for all values of intergrain separation both in the plasma as well as in the plasma sheath. The predicted cohesive energy assumes a form familiar from molecular physics but with no ad hoc assumptions regarding the form of the repulsive and attractive regions and no phenomenologial adjustable parameters. The result is significant as a molecular model and constitutes an important element for understanding the interaction forces responsible for the formation of the novel Coulomb or plasma crystal systems. (C) 1998 Elsevier Science B.V.