Electrostatic screening in classical Coulomb fluids: exponential or power-law decay or both? An investigation into the effect of dispersion interactions

摘要: It is shown that the nature of non-electrostatic part pair interaction potential in classical Coulomb fluids can have a profound influence on screening behaviour. Two cases are compared: (i) when equals an arbitrary finite-ranged and (ii) dispersion r -6 included. A formal analysis done exact statistical mechanics, including investigation bridge function. found Coulombic -1 potentials coupled very intricate manner as regards The one-component plasma (OCP) particularly clear example due to its simplicity investigated detail. When turned on, screened electrostatic from particle goes monotonic exponential decay, exp(-κr)/r, power-law -8 , for large r. distribution function acquire, at same time, -10 decay instead one. There still remains exponentially decaying contributions both functions, but these turn oscillatory switched on. off kept, over behaviour, which normal one electroneutral particles with interactions. Differences similarities compared binary electrolytes pointed out.