[QE-users] ghost like bands ?
Dear all, I have been checking the SSSP pseudopotentials by applying these to my system (Ba2PrBiO6), but I encountered something strange result when I calculate its band structure. I attached the band structure plot along the gamma to X points. I can obtain the left hand side plot when I use the 'legacy' pseudopotentials. Ba 137.327 Ba.pbe-spn-kjpaw_psl.1.0.0.UPF Pr 140.90765 Pr.pbe-spdn-kjpaw_psl.1.0.0.UPF Bi 208.9804 Bi.pbe-dn-kjpaw_psl.1.0.0.UPF O 15.999 O.pbe-n-kjpaw_psl.1.0.0.UPF These are taken from the 'Ready-to-use PP tables'. http://pseudopotentials.quantum-espresso.org/legacy_tables Where the Fermi level was set to zero eV. We can see the two Bi states at 2 eV. The same band structure plot can be obtained by using the another DFT code (VASP) and I think it is a reliable one. However, if I switch the Pr pseudopotential to the SSSP one (Pr.GGA-PBE-paw-v1.0.UPF) suddenly ghost like states appear at the 2 eV (right hand side plot). I know that there are also the SSSP version for Bi and O but these do not alter the band structure plot (all these resulted in the left hand side plot). I think these 'ghost like bands' at 2 eV are irrelevant states and should not appear in the band structure. Or am I wrong? Any information regarding the above points would be greatly appreciated. 敬具 Best regards --- 西館数芽 Kazume NISHIDATE Ph.D Department of Systems Innovation Engineering, Graduate School of Science and Engineering, Iwate University 4-3-5 Ueda, Morioka, Iwate, 020-8551 JAPAN Phone:+81-19-621-6391 kazume.nishid...@gmail.com, nisid...@iwate-u.ac.jp https://sites.google.com/site/nisidatelab/ Attachment Description: Binary data ___ Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users
Re: [QE-users] users Digest, Vol 175, Issue 20
Tighter converge threshold, probably more k-points for a metal (you must
test it yourself, asking random people on the internet is not always
ideal), but more importantly, read my previous answer.
Regards
--
Lorenzo Paulatto
On Sun, Feb 20, 2022, 20:53 Naharin Jannath
wrote:
> Hello Sally,
>
> Thanks. I modified the input script and the output was promising. But when
> I applied K values 6 6 6 0 0 0. Pressure and cell parameters are again not
> converged. Is there anything I need to increase or decrease when I change K
> values?
>
>
> calculation = 'vc-relax'
> restart_mode = 'from_scratch'
> prefix = 'Nb'
> etot_conv_thr = 1.d-4
> forc_conv_thr = 1.d-3
> pseudo_dir = '.'
> outdir = '.'
> disk_io = 'none'
> tstress = .true.
> tprnfor = .true.
> /
>
> degauss = 0.05
> ecutrho = 360
> ecutwfc = 45
> ibrav = 0
> nat = 1
> ntyp= 1
> occupations = "smearing"
> smearing= "gaussian"
> /
>
> conv_thr = 1.0e-06
> electron_maxstep = 200
> mixing_mode = 'plain'
> mixing_beta = 0.2
> mixing_ndim = 8
> startingpot = "atomic"
> startingwfc = "atomic+random"
> /
>
> ion_dynamics = "bfgs"
> /
>
> cell_dynamics = "bfgs"
> press_conv_thr = 0.01
> /
> ATOMIC_SPECIES
> Nb 92.90638 Nb.pbe-spn-kjpaw_psl.0.3.0.UPF
> ATOMIC_POSITIONS {crystal}
> Nb 0.00 0.00 0.00
> CELL_PARAMETERS {angstrom}
> 1.675751271 1.675751271 1.675751271
> -1.675751271 1.675751271 1.675751271
> -1.675751271 -1.675751271 1.675751271
> K_POINTS {automatic}
> 6 6 6 0 0 0
>
> -
>
> OUTPUT -
>
> pressure -
> total stress (Ry/bohr**3) (kbar) P=
> -47.94
> total stress (Ry/bohr**3) (kbar) P=
> -13.39
> total stress (Ry/bohr**3) (kbar) P=
>2.04
> total stress (Ry/bohr**3) (kbar) P=
>0.03
> total stress (Ry/bohr**3) (kbar) P=
> -0.15
> total stress (Ry/bohr**3) (kbar) P=
> -0.06
> total stress (Ry/bohr**3) (kbar) P=
> -0.30
>
> CELL_PARAMETERS (angstrom)
>1.662099051 1.662099051 1.662099051
> --
> CELL_PARAMETERS (angstrom)
>1.656925425 1.656925425 1.656925425
> --
> CELL_PARAMETERS (angstrom)
>1.657605030 1.657605030 1.657605030
> --
> CELL_PARAMETERS (angstrom)
>1.657613778 1.657613778 1.657613778
> --
> CELL_PARAMETERS (angstrom)
>1.657613778 1.657613778 1.657613778
> --
> CELL_PARAMETERS (angstrom)
>1.657613778 1.657613778 1.657613778
>
> On Sun, 20 Feb 2022 at 03:00,
> wrote:
>
>> Send users mailing list submissions to
>> users@lists.quantum-espresso.org
>>
>> To subscribe or unsubscribe via the World Wide Web, visit
>> https://lists.quantum-espresso.org/mailman/listinfo/users
>> or, via email, send a message with subject or body 'help' to
>> users-requ...@lists.quantum-espresso.org
>>
>> You can reach the person managing the list at
>> users-ow...@lists.quantum-espresso.org
>>
>> When replying, please edit your Subject line so it is more specific
>> than "Re: Contents of users digest..."
>>
>>
>> Today's Topics:
>>
>>1. Why is my VC-RELAX not showing converged result? (Naharin Jannath)
>>2. Re: Why is my VC-RELAX not showing converged result? (sally issa)
>>3. Re: Why is my VC-RELAX not showing converged result?
>> (Lorenzo Paulatto)
>>4. Nose-Hoover Chain in CPMD (ustbhh)
>>
>>
>> --
>>
>> Message: 1
>> Date: Sat, 19 Feb 2022 08:58:57 -0800
>> From: Naharin Jannath
>> To: users@lists.quantum-espresso.org
>> Subject: [QE-users] Why is my VC-RELAX not showing converged result?
>> Message-ID:
>> > g1jl4dnehybnn7iczpoo2wevahmmrj7bpm7...@mail.gmail.com>
>> Content-Type: text/plain; charset="utf-8"
>>
>> I ran the VC-RELAX for simple niobium until I get a converged value. But
>> at
>> the bottom of the output, the cell parameter stops changing. Also, the
>> pressure is well below the "pres_conv_thr" which was set to 0.01 in the
>> input file. Can anyone tell me how to fix it? Also, my CELL_PARAMETER vs K
>> curve is not smooth even using large smearing.
>>
>> calculation = 'vc-relax'
>> restart_mode = 'from_scratch'
>> prefix = 'Nb'
>> etot_conv_thr = 0.01
>> pseudo_dir = '.'
>> outdir = '.'
>> disk_io = 'none'
>> tstress = .true.
>> tprnfor = .true.
>> /
>>
>> degauss = 0.05
>> ecutrho = 360
>> ecutwfc = 45
>> ibrav = 0
>> nat = 1
>> ntyp = 1
>> occupations = "smearing"
>> smearing = "gaussian"
>> /
>>
>> conv_thr = 1.0e-08
>> electron_maxstep = 200
>> mixing_mode = 'plain'
>> mixing_beta = 0.5
>> startingpot = "atomic"
>> startingwfc = "atomic+random"
>> /
>>
>> ion_dynamics = "bfgs"
>> /
>>
>> cell_dynamics = "bfgs"
>>
Re: [QE-users] Applicability of DFT+U+J to Anisotropy Calculations
Dear Peter, I don't know how to answer your question 1). As for 2) maybe this paper can help you: PHYSICAL REVIEW B 96, 165132 (2017); DOI: 10.1103/PhysRevB.96.165132 Best regards, Matteo Il giorno ven 18 feb 2022 alle ore 03:30 Peter Stoeckl via users < users@lists.quantum-espresso.org> ha scritto: > Dear all, > > In recent calculations I have been attempting to calculate uniaxial > magnetocrystalline anisotropies in transition-metal magnetic compounds > using DFT+U method. > > As I understand it, these calculations require (a) non-collinear spins > `noncolin = .true.` and (b) DFT+U with both U and J parameter > `lda_plus_u_kind = 1`, as the simpler `lda_plus_u_kind = 0` is > incompatible with non-collinear spin calculations. > (This is occasionally inconvenient, as DFT+U+J itself is not supported for > structural relaxations.) > > 1. Are there any known issues (or theoretical concerns) with using DFT+U+J > in calculations of magnetic anisotropy in QE? > > 2. For reference, I calculate E_MCA = E_IP – E_OP, i.e. the difference in > (SCF) energy between configurations with in-plane and out-of-plane > magnetization respectively, rather than the perhaps easier force theorem > approach. While I don't expect this to change much, does this affect the > considerations from (1), if any? > > Any information (or corrections) regarding the above points would be > greatly appreciated. > > Peter Stoeckl > PhD Candidate, Department of Physics > University of Minnesota > ___ > Quantum ESPRESSO is supported by MaX (www.max-centre.eu) > users mailing list users@lists.quantum-espresso.org > https://lists.quantum-espresso.org/mailman/listinfo/users -- Matteo Cococcioni Department of Physics University of Pavia Via Bassi 6, I-27100 Pavia, Italy tel +39-0382-987485 e-mail matteo.cococci...@unipv.it ___ Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users
[QE-users] Regarding band calculation of BiFeO3
Dear all,
I have been working on bismuth ferrite BiFeO3, from past
few months.
I use NC pseudopotential from pseudodojo and made all the optimization with
respect to cutoff energy, K-points before performing the calculations.
The band calculation shows no bandgap (it has a bandgap of about 2.67 eV),
hence calculations like Berry phase, dielectric and Turbo Lanczos and
others cannot be performed as it is predicted to be a metal.
I solved the bandgap issue with the implementation of Hubbard potential (up
to U= 5 eV for Fe), but this does not solve the issue completely as few of
the calculations do not have the implementation of Hubbard potential in
them. I wanted to know whether I am making any mistake or is there any
workaround so that I can perform the dielectric property calculations for
my material. I am pasting the scf input file if it is of any use. Thanks in
advance
/* Input file*/
calculation = "scf"
restart_mode = 'from _scratch"
max_seconds = 8.64000e+04
pseudo_dir = "."
tprnfor = .TRUE.
prefix = "BFO"
outdir = "./outdir"
tstress = .TRUE.
/
a = 5.645
cosab = 0.5
degauss = 1.0e-02
ecutrho = 9.6e+02
ecutwfc = 8.0e+01
ibrav = 5
nat = 10
nspin = 2
ntyp = 3
lda_plus_u=.true
Hubbard_U(1) =2.0
occupations = "smearing"
smearing = "gaussian"
starting_magnetization(1) = 2.0e-01
starting_magnetization(2) = 0.0e+00
starting_magnetization(3) = 0.0e+00
/
conv_thr = 1.0e-09
electron_maxstep = 200
mixing_beta = 4.0e-01
startingpot = "atomic"
startingwfc = "atomic+random"
/
K_POINTS {automatic}
8 8 8 0 0 0
ATOMIC_SPECIES
Fe 55.84500 Fe.UPF
Bi208.98038 Bi.UPF
O 15.99940 O.UPF
ATOMIC_POSITIONS (crystal)
Fe 0.777130455 0.777130455 0.777130455
Fe 0.277129455 0.277129455 0.277129455
Bi 0.509340660 0.509340660 0.509340660
Bi 0.009340660 0.009340660 0.009340660
O0.563857130 0.956239313 0.116400442
O0.956239313 0.116400442 0.563857130
O0.116400442 0.563857130 0.956239313
O0.616401442 0.456238313 0.063856130
O0.456238313 0.063856130 0.616401442
O0.063856130 0.616401442 0.456238313
/* end of input file */
Regards,
Srihari
Research scholar
Department of Physics
Manipal Institute of Technology
Manipal
___
Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
users mailing list users@lists.quantum-espresso.org
https://lists.quantum-espresso.org/mailman/listinfo/users
