[Wien] Structural relaxation in hybrid calculations
tran at theochem.tuwien.ac.at
tran at theochem.tuwien.ac.at
Wed Aug 8 17:14:09 CEST 2018
Yes it' ok.
On Wednesday 2018-08-08 14:44, Dr. K. C. Bhamu wrote:
>Date: Wed, 8 Aug 2018 14:44:10
>From: Dr. K. C. Bhamu <kcbhamu85 at gmail.com>
>Reply-To: A Mailing list for WIEN2k users <wien at zeus.theochem.tuwien.ac.at>
>To: A Mailing list for WIEN2k users <Wien at zeus.theochem.tuwien.ac.at>
>Subject: [Wien] Structural relaxation in hybrid calculations
>
>Dear Dr. Tran,
>
>I see a workaround for structural relaxation for YS-PBE0.
>
>PBE optimization with "min_lapw ...." or "run_lapw ..... -min' will give relaxed structure at different volumes.
>
>Make another dir and initialize the case and copy all relaxed structure to pwd and do optimization with YS-PBE0 without relaxation and run
>optimize.job
>
>Could you please verify this workaround?
>
>Regards
>Bhamu
>
>
>
>
>On Sat, Aug 4, 2018 at 8:30 PM, <tran at theochem.tuwien.ac.at> wrote:
> No
>
> On Saturday 2018-08-04 16:22, Dr. K. C. Bhamu wrote:
>
> Date: Sat, 4 Aug 2018 16:22:20
> From: Dr. K. C. Bhamu <kcbhamu85 at gmail.com>
> Reply-To: A Mailing list for WIEN2k users <wien at zeus.theochem.tuwien.ac.at>
> To: A Mailing list for WIEN2k users <wien at zeus.theochem.tuwien.ac.at>
> Subject: Re: [Wien] regarding mixing parameter in hybrid calculations
>
> Thanks Dr. Tran,
>
>
>
> My mistake, the standard value is 0.25!!
>
> Yes, I saw the link you provided (response was on my own queries).
>
>
> What is advised there is:
>
>
> "What you get from the optic calculation (the case.epsilon) file is only the electronic part (and not even the whole
> electronic part) of the dielectric
> constant."
>
> To get the ionic part of the static dielectric constant you would need to do the BERRYPI calculations to get Born
> effective charges tensors."
>
>
>
> Do you have any previous experience on how much the properties may vary if we avoid the "ionic part of the dielectric
> constant'?
>
>
>
> Thanks and regards
>
>
>
>
>
>
>
>
> On Sat, Aug 4, 2018 at 7:13 PM, <tran at theochem.tuwien.ac.at> wrote:
> Hi,
>
> First, the standard value is 0.25 and not 0.025.
>
> For the dielectric constant, there was alreday some explanations here:
> https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg14936.html
> https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg14875.html
>
> alpha_opt at V=V_exp means that the dielectric function (and alpha_opt)
> is calculated only at V_exp and then used for all other volumes.
> See also this:
> https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg15531.html
>
> No, it is not mandatory to do PBE calculation before YS-PBE0. Starting
> YS-PBE0 from PBE electron density (case.clmsum) may just help to reduce
> the number of SCF iterations with YS-PBE0.
>
> Of course it is possible to optimize lattice parameters with YS-PBE0.
> You just need to add the "-hf" option in the optimize.job file.
> What is not possible with YS-PBE0 is to optimize the position of
> atoms in the unit cell (because the forces are not implemented for
> YS-PBE0).
>
> FT
>
>
> On Saturday 2018-08-04 14:46, Dr. K. C. Bhamu wrote:
>
> Date: Sat, 4 Aug 2018 14:46:02
> From: Dr. K. C. Bhamu <kcbhamu85 at gmail.com>
> Reply-To: A Mailing list for WIEN2k users <wien at zeus.theochem.tuwien.ac.at>
> To: A Mailing list for WIEN2k users <Wien at zeus.theochem.tuwien.ac.at>
> Subject: [Wien] regarding mixing parameter in hybrid calculations
>
> Dear Dr. Tran,
>
> In the recent past, I did some calculations using YS-PBE0 for MgO and results were well reproduced (wien2k
> Exercise).
>
> I just read your paper (J. Phys.: Condens. Matter 25 (2013)) and get to know that we can control the mixing
> parameter using various
> ways.
>
> 1) Standard value (0.025)
> 2) By fitting (alpa_opt)
> 3) alpa_opt (V=V_exp)
>
> I have queries for option 2 and 3 alpa:
>
> 2) If I am not wrong (after having a detailed search), the value of dielectric constant used to get
> alpa_opt is the value of dielectric
> constant from
> Rel(epsilon) at energy 0.013610 eV, right?
>
> 3) How to get alpa_opt at V-V_exp?
>
>
>
>
>
> My next query is:
>
> It is reported in the Wien2k exercise that to do YS-PBE0 calculations we need to do a simple PBE scf. So
> if we really need to perform
> PBE calculations before
> going to YS-PBE0, I am wondering how to use YS-PBE0 to optimize the lattice parameters and to get
> structural properties?
>
>
> Could you please advice me on my concerns?
>
> * in above text "_" means an underscore.
>
>
> regards
>
>
>
>
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
>
>
>
>
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
>
>
>
>
More information about the Wien
mailing list