On the CD helix band for long helical polymers

The CD helix bands for infinitely long helical polymers are shown tobe composed of two parts: a derivative‐shaped band plus an ordinary Gaussian‐like band. The derivative‐shaped band results from the zero‐order term of an expansion while the Gaussian‐like band results from the first‐order expansion term. However, the intensities of the two bands are shown to be of the same order of magnitude. They are both linear in the coulombic coupling of transition charge densities for polymer transitions. The sum yields a skewed derivative‐shaped band. The shapes of net CD helix bands are shown to not depend on the approximations used for averaging over orientations if the usual systems, such as polypeptides and polynucleotides, are considered in their long‐wave‐length spectral regions.