[Pw_forum] Doubt in celldm(1)
Hi all I have a doubt regarding the value of celldm(1) in the input file for a supercell calculations. Celldm(1) is the lattice constant value. If I am using a supercell constructed by expanding the original lattice constant 'a'? 2 times in all direction, then what will be the value of celldm(1) now? Will it be the original lattice constant 'a' or '2a'? Thanks in advance Regards Padmaja Patnaik Research Scholar Dept of Physics IIT Bombay Mumbai, India -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110422/603f9c08/attachment.htm
[Pw_forum] Charge density inside the core
Dear all, pp.x can save the charge density outside the core. Is there a way to get the charge density inside the core? Thanks in advance! Baowei Liu
[Pw_forum] Doubt in celldm(1)
2a On Fri, Apr 22, 2011 at 2:59 PM, Padmaja Patnaik < padmaja_patnaik at yahoo.co.uk> wrote: > Hi all > > I have a doubt regarding the value of celldm(1) in the input file for a > supercell calculations. Celldm(1) is the lattice constant value. If I am > using a supercell constructed by expanding the original lattice constant > 'a' 2 times in all direction, then what will be the value of celldm(1) now? > Will it be the original lattice constant 'a' or '2a'? > > Thanks in advance > Regards > Padmaja Patnaik > Research Scholar > Dept of Physics > IIT Bombay > Mumbai, India > ___ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110422/d38f745f/attachment.htm
[Pw_forum] why are there two Fermi energies?
Alexander
>Shift in eigenvalues can be seen as produced by external magnetic fiels (a
>Zeeman term) then the state with two different Fermi energies may be
thought of a >true ground state with only one Fermi level but in the
presence of this stabilizing >magnetic field proportional to the difference
in Fermi energies.
Why not a true ground state with one Fermi level and an external plus an
internal magnetic field that is due to the spin polarization, causes a shift
ib the KS energies, and is self adjusted to have thermodynamical
equilibrium, i.e., one Fermi level.
Fixing total magnetization would be equivalent to setting and external
magnetic field, and shifting the eigenvalues would be equivalent to an
internal magnetic field.
By the way, what are the physical restrictions to the values of
tot_magnetization ?
In my system, having 255 electrons, I can fix tehe tot_magnetization to
0.5, 0.7, 1, 1.2, 1.3, 3.0
For 1.5 <= tot_magnetization<2.5 I get error
from set_nelup_neldw : error # 2
tot_magnetization is inconsistent with total number of electrons
well I see the restriction is in this piece of code
the restriction is in this code
if ( ((MOD(NINT(tot_magnetization_),2) == 0) .and.
(MOD(NINT(nelec_),2)==1)) .or. &
((MOD(NINT(tot_magnetization_),2) == 1) .and.
(MOD(NINT(nelec_),2)==0)) ) &
CALL errore(' set_nelup_neldw ', &
'tot_magnetization is inconsistent with total number of
electrons ', 2 )
I understand that with integer occupations the magnetization could have only
even or odd integer values values depending on the number of electrons. But,
with smearing, allowing real occupations, what is the problem with having
even magnetization with odd number of electrons or close real values?
Best wishes
--
Eduardo Menendez
Departamento de Fisica
Facultad de Ciencias
Universidad de Chile
Phone: (56)(2)9787439
URL: http://fisica.ciencias.uchile.cl/~emenendez
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[Pw_forum] questions about PWCOND
Dear Alexander Thanks for your reply. Your are right, it was just that no enough digit was print out. Now I obtain 11.6 e-7 transmission and you publish 11.82 e-7, this seems correct to me. Best regards Virginie De : pw_forum-bounces at pwscf.org [mailto:pw_forum-bounces at pwscf.org] De la part de Alex Smogunov Envoy? : mardi 19 avril 2011 11:14 ? : PWSCF Forum Objet : Re: [Pw_forum] questions about PWCOND Dear Virginie. 2011/4/18 TRINITE Virginie mailto:virginie.trinite at thalesgroup.com>> Dear all, I try to use PWCOND, and I have two questions: >In which units are the boundary in the input file (bdl, bds, bdr)? They are in alat units. >I have run the two examples 12 and 22 without problem and found results in >agreement with the publications but when I try a more heavy system, I obtain zero conductance. The example that I have used, is the Magnetic Tunnel Junction given in Alexandre Smogounov's home page. The program finished normally without error or complain but all the transmission are nearly zero. I didn't check any convergence, because I want only to test the program. Did I miss something? I think it is normal since here you have a tunneling through an insulating spacer and TMR effects. The conductances should get larger if you decrease the number of isolating layers. All the best, Alexander ___ Pw_forum mailing list Pw_forum at pwscf.org<mailto:Pw_forum at pwscf.org> http://www.democritos.it/mailman/listinfo/pw_forum -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110422/193df8e5/attachment-0001.htm
