Structural information in the local electric field produced by helical charge
distributions, such as dissolved DNA, is revealed in a straightforward manner
employing cylindrical coordinates. Comparison of structure factors derived in
terms of cylindrical and helical coordinates is made. A simple coordinate
transformation serves to relate the Green function in cylindrical and helical
coordinates. We also compare the electric field on the central axis of a single
helix as calculated in both systems.Comment: 11 pages in plain LaTex, no figures. Accepted for publication in PRE
March, 199