FIG. 5.
Ratio of the first triplet energy (T) calculated within GW-BSE diagonalizing the full BSE Hamiltonian and using the TDA. Several representative GW-BSE schemes are shown: G0W0-BSE@BHLYP in blue line with crosses, G0W0-BSE@OTRSH-PBE in orange line with circles, and evGW-BSE@PBE0 in black line with crosses. GW-BSE predicts a negative triplet energy (shown at zero) for hexacene for all GW schemes used in this work.