Multiwfn forum / Double states

Re: Double states

dummy@example.com (solan) — Sun, 12 Oct 2025 18:39:35 +0000

Thank you very much !!

Re: Double states

dummy@example.com (sobereva) — Wed, 08 Oct 2025 09:31:12 +0000

It you focus on local excitation, B3LYP or PBE0 is a reasonable choice. If there are charge-transfer excitations, wB97XD or CAM-B3LYP would be better for them (but they often overestimate excitation energy of local excitations)

Re: Double states

dummy@example.com (solan) — Wed, 08 Oct 2025 07:26:27 +0000

Thank you very much for your quick and insightful response; it has made the concept much clearer to me, and I will investigate it in more depth. Likewise, which functional would be suitable for studying this type of radical? I have seen that many people use B3LYP directly, but that seems to be a convenient choice rather than the result of a methodical study. Would ωB97X-D be appropriate?

Re: Double states

dummy@example.com (sobereva) — Wed, 08 Oct 2025 00:25:46 +0000

You need to check , if an excited state can be regarded as a doublet state, its should be close to 0.75 (for example, 0.82 is acceptable, but 1.01 cannot be regarded as doublet, indicating it has significantly spin contamination)

Double states

dummy@example.com (solan) — Mon, 06 Oct 2025 10:11:31 +0000

First of all, I would like to express my appreciation for your versatile and useful program. I am currently performing calculations on Trityl (triphenylmethyl) radicals, which are doublet ground-state systems. When computing their excited states using TD-DFT in Gaussian, how can I identify the corresponding D₁ and D₂ energies? Are they simply the first two states listed in the output?

I notice that both states have very similar energies, with a difference of only about 0.01 nm, which seems somewhat counterintuitive to me.

Thank you very much in advance for your assistance.