The energy level band structure of a hypothetical modification of carbon, C2(4), (authors, 1981-82), was calcd. by the MO LCAO method within 1-electron approxn., with consideration of nearest-neighbor interaction. The C2(4) modification is formed as a result of regular bonding of C chain macromols. having 4-th order spiral axes of different chirality (41 and 43). This modification has a band structure characteristic for semiconductors with a wide band gap (1.2-2.2 eV, depending on the crystallog. parameters).