[QE-users] Initializing triplet state from OCCUPATIONS = input

[Giuseppe Mattioli]

Dear Brendan
It is apparently the opposite. Cyanide ion CN- is isoelectronic with  
CO, and it is a diamagnetic ion. The expected result should be  
therefore that you have found. However, be careful. As opposed to HCN,  
CN- should not be stable in gas phase. Check your results, because due  
to such an instability, an due to the limitations of GGA  
exchange-correlation functionals, your HOMO might be unbound.
HTH
Giuseppe

Brendan Smith <bsmith24 at buffalo.edu> ha scritto:

> Hello QE experts.
>
> I am trying to initialize a triplet ground state in which 2 unpaired
> electrons (either both alpha or both beta) exist. Can someone please take a
> look a my input to see if everything looks OK? Attached is my input file.
> Please note, that an extra electron has been added to the cell, giving a -1
> overall charge.
>
> Apparently, such a triplet state is supposed to be energetically lower than
> the singlet ground state, but I find the singlet ground state to be lower
> in energy.
>
> Thank you,
> Best,
> Brendan A. Smith
> State University of New York at Buffalo



GIUSEPPE MATTIOLI
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