To speedup an MD simulation, Rycerz and Jacobs [42] suggested that by properly choosing
the simulation parameters, the reciprocal-space sum contribution to the total energy can be neglected
entirely.
For MD simulations of 
, one with N=270 and another with N=2160, 
, and using
the minimum image convention, the authors estimated the contribution of reciprocal potential (
)
to total potential (U) to be about 
.
Similar observations were made for a crystalline and molten NaCl system.
It was pointed out [42] however, that this approach should not be applied to small systems
as the energy becomes strongly dependent on the system's configuration.
Moreover, there is no indication that other ionic systems will have similar
small 
contribution to the energy. It is also unclear whether the method can be extended to
polar systems. Therefore, this method requires more investigation and is currently limited to
large ionic systems and hence is not recommended for general MD simulations.