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[youcef <bouhadda@yahoo.com>]

dear users,
I am a biginer abiniter. now I try to stydy NaMgH3 and the relative enthalpie
of formation :
1- for NaMgH3 the relaxation and the optimization of volume (celle parametres 
)
with abinit go fine ( no probleme in the Scf cycles).
2-but when  i do the same thing (structure optimization) for NaH using this
input file:
#structure et energie total de NaH
#Definition de la maille elementaire
#**********************************
   acell 4.8900 4.8900 4.8900 angstrom
#   angdeg 90.0 90.0 90.0
rprim 1.0 0.0 0.0
      0.0 1.0 0.0
      0.0 0.0 1.0
#Definition des atomes
#*********************
   natom 2
   ntypat 2
   znucl 11 1
   typat 1 2
   xred  0.00000000 0.00000000 0.00000000
         0.50000000 0.50000000 0.50000000         
## geom part ends ##
ixc 11
#Definition de la procedure scf
#******************************
iscf 7
nstep 200
#Definition de la base d'ondes planes
#************************************
ecut 50
ngkpt 8 8 8
kptopt 1
#Structural relaxation
ionmov 2
optcell 1
ecutsm 0.5
#Structural relaxation
ntime 30
dilatmx 1.05
#*********************
   toldfe 1.0d-07
****************
the output in the end (3 lignes):
At the end of Broyden step  1, total energy= -9.89981836322699E-01 Ha.
 BROYDEN STEP NUMBER   2 
------------------------------------------------------
     iter   Etot(hartree)      deltaE(h)  residm     vres2    diffor    maxfor
*****
So its clear that the calculations stop after two cycle.
In the end of log file there is:
BROYDEN STEP NUMBER   2  
------------------------------------------------------
 Unit cell characteristics (before scfcv) :
  acell=  2.9555905615E+01  2.9555905615E+01  2.9555905615E+01
  rprim=  1.0000000000E+00  0.0000000000E+00  0.0000000000E+00
          0.0000000000E+00  1.0000000000E+00  0.0000000000E+00
          0.0000000000E+00  0.0000000000E+00  1.0000000000E+00
  ucvol=  2.5818607361E+04 Bohr^3

  xred=
  0.0000000000E+00   0.0000000000E+00   0.0000000000E+00
  5.0000000000E-01   5.0000000000E-01   5.0000000000E-01
 Cartesian coordinates (bohr)
  0.00000000000000E+00  0.00000000000000E+00  0.00000000000000E+00
  1.47779528076982E+01  1.47779528076982E+01  1.47779528076982E+01
 Cartesian forces (hart/bohr); max,rms= 0.00000E+00 0.00000E+00 (free atoms)
  0.00000000000000E+00  0.00000000000000E+00  0.00000000000000E+00
  0.00000000000000E+00  0.00000000000000E+00  0.00000000000000E+00
 

     iter   Etot(hartree)      deltaE(h)  residm     vres2    diffor    maxfor

 chkdilatmx: ERROR -
  The new primitive vectors rprimd (an evolving quantity)
  are too large with respect to the old rprimd and the accompanying dilatmx :
  this large change of unit cell parameters is not allowed by the present 
value
of dilatmx.
  You need at least dilatmx=    3.198429E+00
  Action : increase the input variable dilatmx.

 leave_new : decision taken to exit ... 
**
what is wrong in my input file?
thank you for your help