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["Erik Ylvisaker" <eylvisaker@physics.ucdavis.edu>]

I think your lattice parameters are too small.  Your a lattice parameter is 
3.957 Bohr = 2.094 Angst. but should be 7.48 Angst.  So your total energy is 
much higher than it should be.

----- Original Message ----- 
From: <lichenliang1980@yahoo.com.cn>
To: <forum@abinit.org>
Sent: Tuesday, May 30, 2006 6:30 PM
Subject: Re:Re: [abinit-forum] about total energy


> Hello,
> Many thanks for your help.But my problem are not solved yet.
> Here is my input file.
> ndtset 10
> ecut: 20 ecut+ 2
> acell 3.957 3.957 2.315
> znucl 57 17
> natom 8
> ntypat 2
> typat 1 1 2 2 2 2 2 2
> xred  1/3  2/3  1/4
>     -1/3 -2/3 -1/4
>      0.38741  0.30155  0.25
>     -0.38741 -0.30155 -0.25
>     -0.30155  0.08586  0.25
>      0.30155 -0.08586 -0.25
>     -0.08586 -0.38741  0.25
>      0.08586  0.38741 -0.25
> nstep 100 nband 50 angdeg 90 90 120 kptopt 1 ngkpt 4 4 4
> nshiftk 1
> shiftk 0.0 0.0 0.5   iscf 5 ixc 11 toldfe 1.0d-6
>
> Here is part of the results of calculation about the total energy.
> Components of total free energy (in Hartree) :
>
>    Kinetic energy  =  2.67813630822206E+02
>    Hartree energy  =  1.58763437684854E+00
>    XC energy       = -1.25245008583914E+02
>    Ewald energy    = -4.40741180658962E+02
>    PspCore energy  =  4.18177461902101E+02
>    Loc. psp. energy= -1.31956990942814E+01
>    Spherical terms =  9.80024784350589E+01
>    >>>>>>>>> Etotal=  2.06399317199056E+02
>
> "Double-counting" decomposition of free energy:
>    Band energy     =  2.17506893421672E+02
>    Ewald energy    = -4.40741180658962E+02
>    PspCore energy  =  4.18177461902101E+02
>    Dble-C XC-energy= -2.92833236719089E+01
>    Spherical terms =  4.07397007922429E+01
>    >>>> Etotal (DC)=  2.06399551785145E+02
>
>  >Total energy in eV           =  5.61641118084099E+03
>  >Total DC energy in eV        =  5.61641756425323E+03
> The pseudopotentials needed for this job are ''La_ps.abinit.paw'' and 
> ''Cl_ps.abinit.paw''.
> Is there anything wrong in my calculation ?
>
> Your kind help and suggestions are greatly appreciated!
>
> Thanks
> Li
>
>
>
>
>
>
>
>
>
>
> Hi,
>
> You may have to be more explicit about your problem if you want some
> useful help.
> However:
> -energy in dft calculation is usualy negative
> -energy is not absolute. you can only compare the energy of different
> systems. It is possible that the specific pseudo you use or the
> configuration of your system is such that the energy is positive with
> respect to your reference...
> -For more fruitful exchange I would advice (like Mikami-san) that you
> follow the abinit netiquette (see
> http://www.abinit.org/community/?text=netiquette). People would find
> it easier to help you if they now what your doing.
>
> best regards
>
> PMA
>
> On 5/30/06, lichenliang1980@yahoo.com.cn <lichenliang1980@yahoo.com.cn>
> wrote:
> > Hello,
> >     I had computed the rare-earth halids with PAW method but I
> obtained the total energy that is positive number. Someone else computed 
> the
> total energy of rare-earth halids that is negative. I refered to some
> literatures and found that the total energy of other materials is almost
> negative.So I want to ask if the total energy should be negative.If the
> total energy should be negative ,I should how to modify my result.
> > Thanks
> > li
>
>
>
> --
> Pierre-Matthieu Anglade