Comparison of extended Hückel and CNDO/2 TCNQ and TTF bandwidths in TTF-TCNQ (tetrathiafulvalinium-tetracyanoquinodimethane)

CNDO/2 TCNQ and TTF bandwidths obtained from dimer splittings have been previously calculated and found to be significantly larger than the values obtained from other methods. A comparison of CNDO/2 and extended Hückel results indicates that this primarily arises from the neglect of the off-diagonal overlap integrals. © 1978.