[Pw_forum] Total energy value in QE, strange value.

[joaquin peralta]

Dear Forum,

I calculated the energy of a aluminium surface, but the value that i
obtained using this is 'extremely high'  energy, i obtain the same using
4.2.1 and 4.1 version of QE.

My input file is :
=========================================
&CONTROL
   calculation           = 'scf'
   prefix                = 'al-111-43.5'
   tprnfor               = .true.
   wfcdir                = './restore/'
   pseudo_dir            = '/home/jperalta/pseudo/'
   outdir                = './restore'
/
&SYSTEM
   ibrav                 =  0
   celldm(1)             =  1.0
   nat                   = 21
   ntyp                  = 1
   ecutwfc               = 30
   ecutrho               = 500
   degauss               = 0.03
   occupations           = 'smearing'
   smearing              = 'mv'
   nspin                 = 2
   starting_magnetization= 0.1
   nbnd                  = 300
/
&ELECTRONS
   electron_maxstep      = 300
   mixing_mode           = 'local-TF'
   mixing_beta           = 0.3
   mixing_ndim           = 10
/
&IONS
!   ion_dynamics          = 'bfgs'
/
&CELL
!   cell_dynamics         = 'bfgs'
!   press                 = 0.0D0
!   press_conv_thr        = 0.1D0
/
ATOMIC_SPECIES
Al  26.982 Al.pbe-sp-van.UPF
ATOMIC_POSITIONS (angstrom)
Al   4.295143   -2.479802   43.5
Al   5.726858   -3.306403   41.689899
Al   1.431714   -0.826601   41.689899
Al   2.863429   -3.306403   41.689899
Al   4.295143   -0.826601   41.689899
Al   2.863429   -1.653201   39.351919
Al   7.158572   -4.133004   39.351919
Al   5.726858   -1.653201   39.351919
Al   4.295143   -4.133004   39.351919
Al   8.590287   -4.959604   37.013940
Al   4.295143   -2.479802   37.013940
Al   5.726858   -4.959604   37.013940
Al   7.158572   -2.479802   37.013940
Al   5.726858   -3.306403   34.675960
Al   1.431714   -0.826601   34.675960
Al   2.863429   -3.306403   34.675960
Al   4.295143   -0.826601   34.675960
Al   2.863429   -1.653201   32.337980
Al   7.158572   -4.133004   32.337980
Al   5.726858   -1.653201   32.337980
Al   4.295143   -4.133004   32.337980
K_POINTS (automatic)
6 6 6 0 0 0
CELL_PARAMETERS {cubic}
10.822192        0.000000        0.000000
5.411096         -9.372293       0.000000
0.000000         0.000000        139.892407
================================

i change some electrons parameters in order to improve the convergence. I
don't know if the enery problem is caused for some special parameter or some
like that. but in a paper of Sanchez et al (Molecular Physics, 2004, vol
102, 1045-1055), the energies are aroung 2 to 20 eV.

And the ouput in my case say :

    the Fermi energy is    -1.8658 ev

!    total energy              =   -3357.65873780 Ry  ---------------> 2K eV
by atom.
     Harris-Foulkes estimate   =   -3357.65873669 Ry
     estimated scf accuracy    <       0.00000057 Ry

     The total energy is the sum of the following terms:

     one-electron contribution = -110140.98098627 Ry
     hartree contribution      =   54852.05508820 Ry
     xc contribution           =    -409.97773145 Ry
     ewald contribution        =   52341.24991020 Ry
     smearing contrib. (-TS)   =      -0.00501849 Ry

     total magnetization       =     0.00 Bohr mag/cell
     absolute magnetization    =     0.00 Bohr mag/cell

     convergence has been achieved in  34 iterations


Any help i really appreciate it.

Best Regards
Joaquin Peralta
Iowa State University.

-- 
----------------------------------------------------
Group of NanoMaterials
----------------------------------------------------
http://www.gnm.cl
----------------------------------------------------
Joaquín Andrés Peralta Camposano
----------------------------------------------------
http://www.lpmd.cl/jperalta

In a world without frontiers,
who needs Gates and Win.
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