There is no electron repulsion in a d complex, and the single electron resides in the t orbital ground state. A d octahedral metal complex, such as [Ti(HO)], shows a single absorption band in a UV-vis experiment. The term symbol for d is D, which splits into the T and E states. The t orbital set holds the single electron and has a T state energy of -4Dq. When that electron is promoted to an e orbital, it is excited to  the E state energy, +6Dq. This is in accordance with the single absorption band in a UV-vis experiment. The prominent shoulder in this absorption band is due to a Jahn–Teller distortion which removes the degeneracy of the two E states. However, since these two transitions overlap in a UV-vis spectrum, this transition from T to E does not require a Tanabe–Sugano diagram.