The ABINIT Users Mailing List ( CLOSED )

[Bernard Amadon <bernard.amadon@cea.fr>]

Dear Vincent,

With iscf=17 (the default value of iscf),  ETOT
is equal to the so-called "double counting" expression of the energy
written "Etotal (DC)" in the .out file (you could check it in your .out 
file).

Moreover, Etotal and Etotal (DC) (both written in the .out file)
are expected to agree if
your calculation is well converged.
In your case, your convergence criterion
is weak (toldfe 1.d-05) so Etotal and Etotal (DC)
are not equal. You could
increase you convergence criterion to check this.

Best regards
Bernard


Vincent Chevrier a écrit :
> Hi,
>
> I am wondering what the difference is between Etotal and etotal for PAW
> calcs. I can't remember ever seeing a difference stated on the ABINIT
> website. I'm especially interested in knowing how tphysel affects this
> difference.
>
> I completed two runs with the same structure the only difference being
> tphysel=0 and tphysel=0.00213.
>
> >From the .out file:
>
> For tphysel=0:
>     Kinetic energy  =  1.72081044902126E+01
>     Hartree energy  =  1.17823500013938E+01
>     XC energy       = -3.59810665254476E+01
>     Ewald energy    = -1.07436906857906E+02
>     PspCore energy  =  8.93535605840166E+00
>     Loc. psp. energy= -4.47984809673791E+01
>     Spherical terms = -7.44950150296981E+01
>     >>>>> Internal E= -2.24785658830422E+02
>
>     -kT*entropy     =  2.10993387856660E-04
>     >>>>>>>>> Etotal= -2.24785447837035E+02
> and
>     etotal  -2.2478510911E+02
>
> For tphysel=0.002131
>     Kinetic energy  =  1.72075689848333E+01
>     Hartree energy  =  1.17845516746048E+01
>     XC energy       = -3.59818457081452E+01
>     Ewald energy    = -1.07436906857906E+02
>     PspCore energy  =  8.93535605840166E+00
>     Loc. psp. energy= -4.48011025224259E+01
>     Spherical terms = -7.44958705044103E+01
>     >>>>> Internal E= -2.24788248875047E+02
>
>     -kT*entropy     =  2.50366407550064E-03
>     >>>>>>>>> Etotal= -2.24785745210972E+02
> and
>     etotal  -2.2478486425E+02
>
> below is the input file. Can anybody help me understand:
> 1 - the cause of the difference between Etotal and etotal
> 2 - the effect of tphysel on the difference between Etotal and etotal
>
> Thanks
> Vincent
>
> Input file:
>
>     ndtset   2
>    tphysel1  0.002131
>    tphysel2  0.0
>     occopt   4
>     tsmear   0.01
>
>  pawecutdg   15
>       ecut   15
>     kptopt   1
>    nshiftk   1
>     shiftk   0.5 0.5 0.5
>   kptrlatt   6  0  0
>              0  3  0
>              0  0 10
>
>      nstep   50
>     toldfe   1.0d-5
>
>     ntypat   2
>      znucl   3 14
>      natom   34
>      typat   1  1  1  1  2  1  1  1
>              2  1  1  1  2  1  1  1
>              2  1  1  1  1  2  1  1
>              1  2  1  1  1  2  1  1
>              1  2
>
>      acell   1.5065427965E+01  2.8615352526E+01  8.4083802112E+00 Bohr
>      rprim   1.0 0.0 0.0
>              0.0 1.0 0.0
>              0.0 0.0 1.0
>
>       xred   7.4996953092E-13  5.0000000000E-01  0.0000000000E+00
>              9.6480532055E-02  1.9420479791E-01  0.0000000000E+00
>              2.7080350417E-01  3.4610078252E-01  0.0000000000E+00
>              1.5292044305E-01  2.5787557735E-02  0.0000000000E+00
>              4.1748605305E-01  1.6031572532E-01  0.0000000000E+00
>              2.5955975937E-01  9.5181187368E-02  5.0000000000E-01
>              4.0978302750E-01  2.5635768786E-01  5.0000000000E-01
>              9.6925526499E-02  3.9393640703E-01  5.0000000000E-01
>              4.2837868374E-01  4.3177429281E-01  5.0000000000E-01
>              9.0351946795E-01  8.0579520209E-01  0.0000000000E+00
>              7.2919649583E-01  6.5389921748E-01  0.0000000000E+00
>              8.4707955695E-01  9.7421244227E-01  0.0000000000E+00
>              5.8251394695E-01  8.3968427468E-01  0.0000000000E+00
>              7.4044024063E-01  9.0481881263E-01  5.0000000000E-01
>              5.9021697250E-01  7.4364231214E-01  5.0000000000E-01
>              9.0307447350E-01  6.0606359297E-01  5.0000000000E-01
>              5.7162131627E-01  5.6822570719E-01  5.0000000000E-01
>              5.0000000000E-01  0.0000000000E+00  0.0000000000E+00
>              4.0351946795E-01  6.9420479791E-01  0.0000000000E+00
>              2.2919649583E-01  8.4610078252E-01  0.0000000000E+00
>              3.4707955695E-01  5.2578755773E-01  0.0000000000E+00
>              8.2513946947E-02  6.6031572532E-01  0.0000000000E+00
>              2.4044024063E-01  5.9518118737E-01  5.0000000000E-01
>              9.0216972503E-02  7.5635768786E-01  5.0000000000E-01
>              4.0307447350E-01  8.9393640703E-01  5.0000000000E-01
>              7.1621316266E-02  9.3177429281E-01  5.0000000000E-01
>              5.9648053206E-01  3.0579520209E-01  0.0000000000E+00
>              7.7080350417E-01  1.5389921748E-01  0.0000000000E+00
>              6.5292044305E-01  4.7421244227E-01  0.0000000000E+00
>              9.1748605305E-01  3.3968427468E-01  0.0000000000E+00
>              7.5955975937E-01  4.0481881263E-01  5.0000000000E-01
>              9.0978302750E-01  2.4364231214E-01  5.0000000000E-01
>              5.9692552650E-01  1.0606359297E-01  5.0000000000E-01
>              9.2837868374E-01  6.8225707188E-02  5.0000000000E-01
>
>
>
>
>