Fig. 8.

Comparison of proposed model with AFM observation of Type I G-wires. a Schematic representation of − 90° rotamer of the "(2,2) Diagonal" model containing 15 G-tetrad blocks, corresponding to a length of ~ 20 nm. b The G-wire structural model for the − 90° rotamer of the "(2,2) Diagonal" arrangement in two different molecular orientations. Thymines are shown in orange. c Surface representation of the above structures, where the grayscale intensity is related to the distance from the plane over which the molecule is lying. Atomic radii for Thymines have been altered for visualization purposes. d AFM images generated by simulated scanning with a paraboloid AFM tip. The length scale (white bar) is 4 nm. e Experimentally observed AFM images of Type I G-wires showing two types of periodic surface features