<div dir="ltr">Dear Prof. Laurence, Prof. Gerhard & Prof. Peter,<br><div><br></div><div> Thank you so much for your valuable advices. I will try all the options & will let you know the results within a few days.</div><div><br></div><div>with best regards,</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, 29 Jan 2020 at 00:59, Peter Blaha <<a href="mailto:pblaha@theochem.tuwien.ac.at">pblaha@theochem.tuwien.ac.at</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">First of all, the VASP gaps of bulk SnS2 are 1.91 eV, not 2.1 as you are <br>
writing ?????<br>
<br>
<br>
Then there are other VASP papers, which report different results, in <br>
particular different structural parameters:<br>
<br>
(Phys. Chem. Chem. Phys., 2016, 18, 318)<br>
a=3.693 c=11.680 gap: 1.91<br>
<br>
<a href="https://doi.org/10.1016/j.actamat.2014.03.042" rel="noreferrer" target="_blank">https://doi.org/10.1016/j.actamat.2014.03.042</a>:<br>
a = 3.518 Å, c = 5.844 Å), gap 1.92 eV (also PBE+U(9 eV !!<br>
<br>
SnS2 is a layered material and all VASP papers used a DFT-D2 (+U) <br>
approach. It could be that your Sn position is quite different from <br>
theirs ???<br>
<br>
PS: I would not reduce the RMTs. You will make the effect of U even <br>
smaller with smaller RMTs.<br>
<br>
PPS:<br>
I'd use TB-mBJ or hybrid-DFT for band gaps- but you said, band gaps are <br>
not your focus, but the voltage of LiSnO2.<br>
<br>
For this you need good structural parameters AND good cohesive energies.<br>
<br>
I'd use a vdW-functional (for instance rev-vdW-DF2, see our paper) to <br>
optimize the structure and also the SCAN meta-GGA for the energies (the <br>
formation energy determines the Voltage).<br>
<br>
<br>
On 1/28/20 3:11 PM, shamik chakrabarti wrote:<br>
> <br>
> Dear Professor Laurence and wien2k users,<br>
> <br>
> with reference to my earlier mail <br>
> on SnS2, I have checked the change in RMT (for avoiding Ghostband) with <br>
> U and corresponding band gap. The details are as follows;<br>
> <br>
> U = 7 eV RMT reduction 6% Band gap = 1.460 eV<br>
> U = 8 eV RMT reduction 15% Band gap= 1.475 eV<br>
> U= 9 eV RMT reduction 30% Band gap = 1.512 eV<br>
> <br>
> I have not able to reproduce the band gap ~ 2.1 eV as computed <br>
> earlier using Vasp (Phys. Chem. Chem. Phys., 2016, 18, 318). Also, <br>
> whether 30% reduction of RMT is acceptable???<br>
> <br>
> Looking forward to further guidance from you.<br>
> <br>
> with regards,<br>
> <br>
> -- <br>
> Dr. Shamik Chakrabarti<br>
> Research Fellow<br>
> Department of Physics<br>
> Indian Institute of Technology Patna<br>
> Bihta-801103<br>
> Patna<br>
> Bihar, India<br>
> <br>
> _______________________________________________<br>
> Wien mailing list<br>
> <a href="mailto:Wien@zeus.theochem.tuwien.ac.at" target="_blank">Wien@zeus.theochem.tuwien.ac.at</a><br>
> <a href="http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien" rel="noreferrer" target="_blank">http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien</a><br>
> SEARCH the MAILING-LIST at: <a href="http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html" rel="noreferrer" target="_blank">http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html</a><br>
> <br>
<br>
-- <br>
<br>
P.Blaha<br>
--------------------------------------------------------------------------<br>
Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna<br>
Phone: +43-1-58801-165300 FAX: +43-1-58801-165982<br>
Email: <a href="mailto:blaha@theochem.tuwien.ac.at" target="_blank">blaha@theochem.tuwien.ac.at</a> WIEN2k: <a href="http://www.wien2k.at" rel="noreferrer" target="_blank">http://www.wien2k.at</a><br>
WWW: <a href="http://www.imc.tuwien.ac.at/TC_Blaha" rel="noreferrer" target="_blank">http://www.imc.tuwien.ac.at/TC_Blaha</a><br>
--------------------------------------------------------------------------<br>
_______________________________________________<br>
Wien mailing list<br>
<a href="mailto:Wien@zeus.theochem.tuwien.ac.at" target="_blank">Wien@zeus.theochem.tuwien.ac.at</a><br>
<a href="http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien" rel="noreferrer" target="_blank">http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien</a><br>
SEARCH the MAILING-LIST at: <a href="http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html" rel="noreferrer" target="_blank">http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html</a><br>
</blockquote></div><br clear="all"><div><br></div>-- <br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div style="font-size:small">Dr. Shamik Chakrabarti</div><div style="font-size:small">Research Fellow </div><div style="font-size:small">Department of Physics</div><div style="font-size:small">Indian Institute of Technology Patna</div><div style="font-size:small">Bihta-801103</div><div style="font-size:small">Patna</div><div style="font-size:small">Bihar, India</div></div></div></div></div></div></div></div>