In the single electron approxn. of LCAO MO the electron spectra was calcd of a hypothetical crystal modification of C formed by crosslinked chains of C macromols. with a spiral symmetry 4. The value of the Fermi energy was detd. and the dependence was found of the MO on wave vector along the symmetry direction.
http://dx.doi.org/10.1007/BF00746150