CT	Charge transfer
KT	Ketotifen Fumarate
DDQ	2,3-dichloro-5,6-dicyano-p-benzoquinone
TCNQ	7,7,8, 8-tetracyanoquinodimethane
DFT	density functional theory
f	oscillator strength
μ	transition dipole moment
Ip	ionization potentials
$E_{CT}$	energy of charge transfer complex
W	dissociation energy
ΔG	Gibbs free energy
RN	Resonance energy
ε	extinction coefficient
MEP	molecular electrostatic potential
HOMO	highest occupied molecular orbital
LUMO	lowest unoccupied molecular orbital