Figure 5.

Dependence of electrostatic interaction energy on azimuthal orientation of neighboring DNA molecules. The dependence of E_int⁽²⁾ + E_int⁽³⁾ on φ′₁ and φ′₂ is shown at R = 23 Å and at optimal Δz for A-DNA helices at f = 0 (A), B-DNA helices at f = 0 (B), and B-DNA helices at f = 0.5 (C). The contours represent lines of constant energy. The values of the energy in the units of thermal energy (k_BT) per base pair are shown by the color code. Different energy landscapes in the pair interaction may lead to different lateral packing of helices in these three cases.