[QE-users] Fwd: Absorption spectra for systems with unpaired electrons (Yang Liu)

[Matthew Marcus]

I asked Yang Ha, who just did a workshop on Orca, about this problem. 
Here's what he had to say:
	mam


-------- Forwarded Message --------
Subject: 	Re: [QE-users] Absorption spectra for systems with unpaired 
electrons (Yang Liu)
Date: 	Fri, 13 Aug 2021 08:41:07 -0700
From: 	Yang Ha <YangHa at lbl.gov>
To: 	Matthew Marcus <mamarcus at lbl.gov>



Hi Matthew,
I am not too sure about what he means by systems with unpaired 
electrons. If he means open shell singlet, then it is not a software 
issue, but method issue. ORCA has the function to do so called Brokensym.
However, the excitation state of O2 can be tricky, because there are two 
types of singlet oxygen. I actually posted a question on the ORCA forum 
a few years ago
https://orcaforum.kofo.mpg.de/viewtopic.php?f=8&t=5923&p=25407#p25407 
<https://orcaforum.kofo.mpg.de/viewtopic.php?f=8&t=5923&p=25407#p25407>
That is why I raised the same question to Ali yesterday. The (Detla)SCF 
method could be a solution to that. He/she really should attend our 
workshop :)
Yang


On Fri, Aug 13, 2021 at 8:19 AM Matthew Marcus <mamarcus at lbl.gov 
<mailto:mamarcus at lbl.gov>> wrote:

     This question came through the Quantum Espresso forum.  Does Orca do
     TDDFT with unpaired electrons correctly?  If so, I could suggest it
     to him.
              mam


     -------- Forwarded Message --------
     Subject:        [QE-users] Absorption spectra for systems with unpaired
     electrons (Yang Liu)
     Date:   Fri, 13 Aug 2021 12:33:38 +0800
     From:   Yang Liu <rabbitkiller at 163.com <mailto:rabbitkiller at 163.com>>
     Reply-To:       Quantum ESPRESSO users Forum
     <users at lists.quantum-espresso.org
     <mailto:users at lists.quantum-espresso.org>>
     Organization:   FDU
     To:     users <users at lists.quantum-espresso.org
     <mailto:users at lists.quantum-espresso.org>>



     Dear all

     I am wondering if I can calculate the absorption spectra for systems
     with unpaired electrons, e.g. O2 molecule,  in QE. It seems that the
     TDDFT modules (both turbo_lanczos and turbo_davidson) do not handle
     spin-polarized calculations, the GWW module don't either.

     Could you please help me on this?

     Thanks & Regards