  We study the role of the effective Coulomb interaction strength and length on
the dynamics of nucleons in conditions according to those in a neutron star's
crust. Calculations were made with a semi-classical molecular dynamics model,
studying isospin symmetric matter at sub-saturation densities and low
temperatures. The electrostatic interaction between protons interaction is
included in the form of a screened Coulomb potential in the spirit of the
Thomas-Fermi approximation, but the screening length is artificially varied to
explore its effect on the formation of the non-homogeneous nuclear structures
known as "nuclear pasta". As the screening length increases, we can a
transition from a one-per-cell pasta regime (due exclusively to finite size
effects) to a more appealing multiple pasta per simulation box. This shows
qualitative difference in the structure of neutron star matter at low
temperatures, and therefore, special caution should be taken when the screening
length is estimated for numerical simulations.
