Multiwfn forum / HOMO LUMO gap of open shell molecule

Re: HOMO LUMO gap of open shell molecule

dummy@example.com (Abdullah) — Thu, 28 Jan 2021 17:04:02 +0000

Thanks professor

dummy@example.com (sobereva) — Thu, 28 Jan 2021 14:47:21 +0000

For open-shell systems, you should respectively discuss HOMO-LUMO gap for alpha and beta spins, see e.g. PHYSICAL REVIEW B, 77, 035411 (2008)

dummy@example.com (Abdullah) — Thu, 28 Jan 2021 13:16:11 +0000

Hi,
How to calculate HOMO LUMO gap of open shell system? is it difference of α-HOMO and α-LUMO or difference of β-HOMO and β-LUMO?