[Pw_forum] shape of the wave function in reciprocal space
Issam AD Issam
maspi2016peace at gmail.com
Fri May 26 13:37:29 CEST 2017
Dear PWSCF users,
I'm a beginner in quantum espresso, i tried to run a relaxation
calculation of α-Al2O3. i always receive an error in relax.out i checked
the atomic positions and the lattice parametters i made sure that they are
exactly saved in input, i will show you the input file if you can help me.
Many thanks in advance,
&control
calculation = 'relax'
restart_mode = 'from_scratch'
prefix = 'AlO'
tstress = .true.
tprnfor = .true.
pseudo_dir = '/home/isam/Public/upf_files/'
outdir = './scratch/'
verbosity = 'high'
etot_conv_thr = 1e-7
forc_conv_thr = 1e-6
nstep = 5000
wf_collect = .true.
&system
ibrav = 5
celldm(1) = 9.6945
celldm(4) = 0.56957
nat = 10
ntyp = 2
nbnd = 14
ecutwfc = 20
nr1 = 30
nr2 = 18
nr3 = 72
&electrons
diagonalization = 'david'
mixing_mode = 'plain'
mixing_beta = 0.7
conv_thr = 1e-9
electron_maxstep = 999
/
&ions
trust_radius_ini = 0.100
ion_dynamics = 'bfgs'
/
&cell
cell_dynamics = 'bfgs'
wmass = 0.0001
press = 0
cell_factor = 2
/
ATOMIC_SPECIES
O 15.99940 O.pw91-van_ak.UPF
Al 26,9815386 Al.pbe-mt_fhi.UPF
ATOMIC_POSITIONS crystal
Al 0.352 0.352 0.352
Al -0.352 -0.352 0.352
Al 0.852 0.852 0.852
Al 0.148 0.148 0.148
O 0.556 -0.056 0.250
O -0.056 0.250 0.556
O 0.250 0.556 -0.056
O 0.556 1.056 -0.250
O 1.056 -0.250 -0.556
O -0.250 -0.556 1.050
K_POINTS automatic
14 14 14 3*0
2017-05-26 6:22 GMT+00:00 Jacopo Simoni <simonij at tcd.ie>:
> Ok many thanks for the help
>
> Best regards, Jacopo Simoni
>
> On 26 May 2017 at 00:03, Paolo Giannozzi <p.giannozzi at gmail.com> wrote:
>
>> Yes
>>
>> On Fri, May 26, 2017 at 8:01 AM, Jacopo Simoni <simonij at tcd.ie> wrote:
>> > Many thanks for the answer.
>> >
>> > This means that the G+k points written in the gkvectors.xml file are the
>> > ones such that
>> >
>> > \hbar^2|k+G|^2/(2m) < Ecut
>> >
>> > and they form a sphere not a parallelepiped
>> > I am right ?
>> >
>> > On 25 May 2017 at 23:49, Paolo Giannozzi <p.giannozzi at gmail.com> wrote:
>> >>
>> >> Only plane waves with \hbar^2(k+G)^2/(2m) < Ecut are included. The
>> >> regular grid in G-space must be large enough to include all of them,
>> >> but it also includes a significant amount of plane waves that exceed
>> >> the cutoff.
>> >>
>> >> Paolo
>> >>
>> >> On Fri, May 26, 2017 at 2:46 AM, Jacopo Simoni <simonij at tcd.ie> wrote:
>> >> > Dear PWSCF users,
>> >> >
>> >> > I am doing a simple scf calculation for a system of 100 Hydrogen
>> atoms
>> >> > in a
>> >> > simple cubic cell.
>> >> >
>> >> > I am generating the wave functions with wf_collect=.true. for a
>> single K
>> >> > vector (0,0,0).
>> >> >
>> >> > From the scf output I realized that the total number of G vectors
>> >> > printed on
>> >> > the file is 847. I am using ecutwfc=20.0 and the shape of the
>> Kohn-Sham
>> >> > matrix is
>> >> >
>> >> > Kohn-Sham wave functions dimensions=(847, 52)
>> >> >
>> >> > where 52 corresponds to the number of bands that I am using in the
>> >> > calculation.
>> >> >
>> >> > However, I am wondering why in the gkvectors.xml file I have a list
>> of G
>> >> > vectors ranging between -5 and 5 times 2*pi / a (a is the lattice
>> >> > parameter)
>> >> > along each primitive lattice direction.
>> >> >
>> >> > The total number of points in such a regular grid should be 11*11*11
>> =
>> >> > 1331
>> >> > that is clearly different from 847. What is the meaning of the
>> missing
>> >> > 484 G
>> >> > vectors in the grid ? I am a bit confused could you please explain
>> to me
>> >> > these results ?
>> >> >
>> >> > Many thanks in advance,
>> >> >
>> >> > Jacopo Simoni,
>> >> > Los Alamos National Laboratory
>> >> >
>> >> > _______________________________________________
>> >> > Pw_forum mailing list
>> >> > Pw_forum at pwscf.org
>> >> > http://pwscf.org/mailman/listinfo/pw_forum
>> >>
>> >>
>> >>
>> >> --
>> >> Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
>> >> Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
>> >> Phone +39-0432-558216, fax +39-0432-558222
>> >> _______________________________________________
>> >> Pw_forum mailing list
>> >> Pw_forum at pwscf.org
>> >> http://pwscf.org/mailman/listinfo/pw_forum
>> >
>> >
>> >
>> > _______________________________________________
>> > Pw_forum mailing list
>> > Pw_forum at pwscf.org
>> > http://pwscf.org/mailman/listinfo/pw_forum
>>
>>
>>
>> --
>> Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
>> Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
>> Phone +39-0432-558216, fax +39-0432-558222
>> _______________________________________________
>> Pw_forum mailing list
>> Pw_forum at pwscf.org
>> http://pwscf.org/mailman/listinfo/pw_forum
>>
>
>
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