[QE-users] pw2casino mismatch energy error

[Paolo Giannozzi]

Dear Wai-Ga David,

the "pw2casino" option has a single specific application: to produce files
for the CASINO Quantum Monte-Carlo code.  It can be used for other purposes
as well, but then ... you are on your own. If I remember correctly, it is
not supposed to work for Ultrasoft pseudopotentials and PAW (CASINO works
only for norm-conserving PPs). There is no check on that because users of
CASINO should know.

Paolo

On Thu, Feb 21, 2019 at 3:02 AM Wai-Ga Ho <wdh17 at my.fsu.edu> wrote:

> Hello QE community,
>
>
> I am currently attempting to extract the kinetic energy contributions to
> the total energies of different polymorphs of MgO.
>
>
> I understand that we need to use the -pw2casino flag if we want our PWSCF
> output to print a more detailed breakdown of the total energy in terms of
> its contributions. This means that using the command:
>
> mpirun -np 4 pw.x  <project.in> project.out
>
>
> will produce a project.out file which contains some text like this:
>
>
> !    total energy              =    -183.20894402 Ry
>      Harris-Foulkes estimate   =    -183.20894409 Ry
>      estimated scf accuracy    <       0.00000009 Ry
>
>      total all-electron energy =      -551.326109 Ry
>
>      The total energy is the sum of the following terms:
>
>      one-electron contribution =     -85.45759185 Ry
>      hartree contribution      =      47.93001020 Ry
>      xc contribution           =     -25.22704816 Ry
>      ewald contribution        =     -95.91150866 Ry
>      one-center paw contrib.   =     -24.54280555 Ry
>
>
> while adding the -pw2casino flag and running:
>
> mpirun -np 4 pw.x -pw2casino <project.in> project.out
>
>
> will print the original lines above, as well as additional lines like:
>
>  Energies determined by pw2casino tool
>  -------------------------------------
>  Kinetic energy      21.442363717309750       au  =
>  42.884727434619499       Ry
>  Local energy       -84.609446621660297       au  =
> -169.21889324332059       Ry
>  Non-Local energy    20.438286977076853       au  =
>  40.876573954153706       Ry
>  Ewald energy       -47.955754330605572       au  =
> -95.911508661211144       Ry
>  xc contribution    -12.613524077939315       au  =
> -25.227048155878631       Ry
>  hartree energy      23.965005100370561       au  =
>  47.930010200741123       Ry
>  Total energy       -79.333069235448022       au  =
> -158.66613847089604       Ry
>
>
> From the above output lines, we can see that the total energies (-183.20894402
> Ry and  -158.66613847089604 Ry) are pretty terribly mismatched. I find
> that this mismatch occurs when using either PWSCF v5.0.2 and PWSCF v6.0.
> When I was using PWSCF v6.0, quantum-espresso actually prints an "Energy
> mismatch error" (I'd paste the error below but my laptop, which runs v6.0,
> is currently in the shop), so at least it recognizes that something is
> wrong.
>
> I've tried looking through some other threads and attempted to apply fixes
> that worked for other people, such as adding the following line:
>
> assume_isolated = 'mp'
>
> to my &CONTROL in my input file (source:
> http://lists.quantum-espresso.org/pipermail/users/2015-April/032059.html),
> but nothing so far has worked.
>
> Does anyone have any idea what the issue is and how to resolve it?
> Because with the demonstrated mismatch in total energies, I do not have
> faith in the kinetic energy value that is output. If this helps, I am using
> the following pseudopotentials:
>
> file Mg.pbe-spnl-kjpaw_psl.1.0.0.UPF: wavefunction(s)  2P renormalized
>
> file O.pbe-nl-kjpaw_psl.1.0.0.UPF: wavefunction(s)  2S 2P renormalized
>
>
> and below is my input file for MgO in a CsCl-type crystalline arrangement
> (which generated the energy values I gave above, using PWSCF v5.0.2):
>
> &CONTROL
>     calculation = "scf"
>     max_seconds =  8.64000e+04
>     outdir      = "./"
>     prefix      = "MgO_CsCl"
>     pseudo_dir  = "/home/davidho/.burai/.pseudopot"
>     title       = "Working MgO CsCl Structure(SCF)"
>     wf_collect  = .TRUE.
> /
>
> &SYSTEM
>     a           =  2.65994e+00
>     degauss     =  1.00000e-02
>     ecutrho     =  2.00000e+03
>     ecutwfc     =  2.00000e+02
>     ibrav       = 1
>     nat         = 2
>     ntyp        = 2
>     occupations = "fixed"
>     smearing    = "gaussian"
>     assume_isolated = 'mp'
> /
>
> &ELECTRONS
>     conv_thr         =  1.00000e-06
>     electron_maxstep = 200
>     mixing_beta      =  7.00000e-01
>     startingpot      = "atomic"
>     startingwfc      = "atomic+random"
> /
>
> K_POINTS {automatic}
> 10 10 10  0 0 0
>
> ATOMIC_SPECIES
> Mg     24.30500  Mg.pbe-spnl-kjpaw_psl.1.0.0.UPF
> O      15.99940  O.pbe-nl-kjpaw_psl.1.0.0.UPF
>
> ATOMIC_POSITIONS {angstrom}
> Mg      0.000000   0.000000   0.000000
> O       1.329970   1.329970   1.329970
>
>
>
> Any help and further insight into both the problem with and/or the method
> of energy decomposition would be greatly appreciated.
>
> Thank you,
> Wai-Ga David Ho, Department of Physics at Florida State University
>
>
>
>
>
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-- 
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
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