[Pw_forum] smoothing PDOS issue (QE 5.0.2)

[David Grifith]

Dear Paolo

thanks for your reply.

at the end of the following document it was mentioned that

"   Obsolete variables, ignored:
    io_choice
    smoothing   "


http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PROJWFC.html

in the following you can see my input files:

*scf:*
&control
    calculation='scf',
    restart_mode='restart',
    prefix='B',
    pseudo_dir = '../pseudo/',
    outdir='../tmp/',
 /
 &system
    ibrav= 0, celldm(1)=2.75899995, nat= 2, ntyp= 1,
    ecutwfc = 40, ecutrho = 400, occupations='smearing',
smearing='gaussian', degauss=0.001,
    nspin=2, starting_magnetization(1)=1
 /
 &electrons
    conv_thr = 1.0e-10
    mixing_beta = 0.3
 /
CELL_PARAMETERS
1.50000000 0.86600000 0.00000000
1.50000000     -0.86600000 0.00000000
0.00000000 0.00000000 8.00000000
ATOMIC_SPECIES
C  12.0107  C.pbe-rrkjus.UPF
ATOMIC_POSITIONS {alat}
C        0.000000000   0.000000000   0.000000000
C        1.997267588   0.000001338   0.000000000
K_POINTS {automatic}
4 4 1 0 0 0


*nscf:*
&control
    calculation='nscf',
    restart_mode='restart',
    prefix='B',
    pseudo_dir = '../pseudo/',
    outdir='../tmp/',
    wf_collect=.TRUE.
 /
 &system
    ibrav= 0, celldm(1)=2.75899995, nat= 2, ntyp= 1,
    ecutwfc = 40, ecutrho = 400, occupations='tetrahedra',
    nspin=2, starting_magnetization(1)=1
 /
 &electrons
    conv_thr = 1.0e-10
    mixing_beta = 0.3
 /
CELL_PARAMETERS
1.50000000 0.86600000 0.00000000
1.50000000     -0.86600000 0.00000000
0.00000000 0.00000000 8.00000000
ATOMIC_SPECIES
C  12.0107  C.pbe-rrkjus.UPF
ATOMIC_POSITIONS {alat}
C        0.000000000   0.000000000   0.000000000
C        1.997267588   0.000001338   0.000000000
K_POINTS {automatic}
20 20 1 0 0 0

*dos:*
 &dos
    outdir='../tmp/'
    prefix='B'
    fildos='B.dos',
    Emin=-40.0, Emax=20.0, DeltaE=0.1,
    /

*pdos:*
 &projwfc
    outdir='../tmp/'
    prefix='B'
    Emin=-40.0, Emax=20.0, DeltaE=0.1
    ngauss=0, degauss=0.001
    /

overall the only way that I can make my PDOS graphs as smooth as DOS ones
is reducing degauss value to 0.01 ! but in some cases that we study the
proper value for degauss is 0.001 and reducing it we may miss something.
mightn't it ?
We are going to compare a large sets of PDOS and DOS graphs and prefer not
to compare one graph with lots of singularities with the others that are
too smooth. I appreciate your advice in advance. Many Thanks




-- 
Sincerely Yours
David G.
JCU


On Fri, 2013-04-26 at 21:50 +0200, David Grifith wrote:


>* when I set smoothing=0.3 as I did in the old versions of q/e the*>* recent version ignores the smoothing procedure and does nothing to*>* smooth the PDOS graph. *>* *>* I would appreciate if anyone helps me to make PDOS graphs as smooth as*>* DOS ones.*

*
*

on *Sat Apr 27 16:35:42 CEST 2013, Paolo Giannozzi wrote: * *
** *
Not sure what you define as "smooth". The DOS in a true crystal is far
from smooth: it has singularities and you need the tetrahedron method
to have a good DOS. With gaussian broadening, you may need a relatively
large broadening or else you will get a series of spikes, but then
you miss the singularities. dos.x can calculate DOS using tetrahedra
(this is what it should do according to your input data). projwfc.x
cannot calculate PDOS with tetrahedra, if I remember correctly. More
exactly: it could, provided somebody take the existing code that
calculates the PDOS for phonons (it should be routine dos_gam in
matdyn.f90), adapts it to electrons.

Anyway: without a simple test (with outputs) and a definition of
what are the "old" and "recent" versions, it is hard to say more.
I do not remember any recent change in the DOS-producing codes
that may explain the phenomenology you describe.

Paolo

-- 
Paolo Giannozzi, Dept. Chemistry&Physics&Environment,
Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222
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