Dear José Xavier,
Hi.
Smearing for the occupations is used when the levels near HOMO are so close
(commonly in metals near Fermi level) that in consecutive iterations they
may exchange positions and lead to nonconvergence. For semiconductors with
3-5 eV gap I think it won't help.
Bests
Mahmoud Payami
NSTRI, AEOI, Tehran, Iran
From: José Xavier via users <[email protected]>
To: "[email protected]" <[email protected]>
Date: Mon, 1 Nov 2021 00:18:55 +0000 (UTC)
Subject: [QE-users] occupation in biological molecules and band gap
Dear all,
I'm new in QE. The group that I'm working with usually calculates the
properties of biologically relevant molecules, like amino acids, hormones,
neurotransmitters, and drugs, and I would like to introduce the QE code to
the group. Their previous papers have shown that the bandgap of these
crystals is something between 3-5 eV, which I understand to be in the
semiconductor range.
I've watched/read some tutorials about QE, and some of these showed that the
occupation of semiconductors should be "smearing", other ones that it should
be "fixed", but no one showed calculations with this kind of molecules. What
value should I use for the SCF and electronic calculations of the crystals
that I'm going to work on (amino acids, hormones, neurotransmitters, and
drugs)?
*Are there any differences when the molecule has a metal, like the Heme
group?
Besides, I would like to ask if there is a calculation that I could perform
to obtain the bandgap of these molecules. Is it only possible if I create
the band structure figure and calculate the difference between the peaks in
VB and CB?
Thank you for your help,
Sincerely,
José Xavier
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_______________________________________________
Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
users mailing list [email protected]
https://lists.quantum-espresso.org/mailman/listinfo/users
