The electrostatic interaction potential energy for two Debye shielded
macroscopic grains or impurities is obtained for all values of intergr
ain separation both in the plasma as well as in the plasma sheath. The
predicted cohesive energy assumes a form familiar from molecular phys
ics 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 impo
rtant element for understanding the interaction forces responsible for
the formation of the novel Coulomb or plasma crystal systems. (C) 199
8 Elsevier Science B.V.