Thickness-dependent ground-state properties

For larger values of p, helices imwind, i.e., the pitch gets larger and the number of monomers per winding increases. However, helical stmctures still dominate the groimd-state conformations. It should be noted that the simple polymer model is energetically invariant imder helicity reversal, i.e., left-handed helices or segments are not explicitly 

Ground-State energy per monomer mm//V of tubelike polymers with nine monomers as a function of the global radius of curvature constraint p (solid line). For comparison, the energy curve of the perfect a-helix is also plotted (dashed line). The inset shows that for a small interval around p 0.686, the ground-state structure is perfectly o -helical. Also depicted are side and top views of putative ground-state conformations for various exemplified values of p. For the purpose of clarity, the conformations are not shown with their natural thickness. From [243]. 

Now that we have completed these preparatory considerations of ground-state properties, we are going to discuss the thermodynamic behavior of the tube polymers. 

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