[Pw_forum] vc-relax applied to my 60 atom supercell

Elie Moujaes elie.moujaes at hotmail.co.uk
Mon Aug 2 15:47:26 CEST 2010


Dear all,

 

Coming back to my problem of the 60 atom supercell system I am trying to relax. I required a threshold on the force of 1 x 10^-2 and a pressure of 0. The last calculation gave a total force of 0.06 and a Pressure of -1.43. The next calculation started but it stopped at iteration #4. What does that mean? Does it mean that the system cannot be relaxed further? You will find that part of the output below..

 

Thanks for your  help

 

Elie Moujaes

University of Nottingham

NG7 2RD

UK

 

 

convergence has been achieved in  10 iterations

     Forces acting on atoms (Ry/au):


     negative rho (up, down):  0.919E-03 0.000E+00
     atom   1 type  1   force =     0.00944017    0.00012592    0.00000000
     atom   2 type  1   force =    -0.00488708   -0.00213113    0.00000000
     atom   3 type  1   force =     0.00664077    0.00464042    0.00000000
     atom   4 type  1   force =     0.00096759   -0.00458671    0.00000000
     atom   5 type  1   force =     0.01002253   -0.01308239    0.00000000
     atom   6 type  1   force =     0.00799961   -0.00238724    0.00000000
.
.
.
.
.
.
.
.
.
.
     Total force =     0.061991     Total SCF correction =     0.001951


     entering subroutine stress ...


     negative rho (up, down):  0.919E-03 0.000E+00
          total   stress  (Ry/bohr**3)                   (kbar)     P=   -1.43
  -0.00000390   0.00000845   0.00000000         -0.57      1.24      0.00
   0.00000845  -0.00002347   0.00000000          1.24     -3.45      0.00
   0.00000000   0.00000000  -0.00000185          0.00      0.00     -0.27


     number of scf cycles    =  14
     number of bfgs steps    =  11

     enthalpy old            =   -1068.3030395302 Ry
     enthalpy new            =   -1068.3098378481 Ry

     CASE: enthalpy_new < enthalpy_old

     new trust radius        =       0.2403077890 bohr
     new conv_thr            =       0.0000015904 Ry

     new unit-cell volume =   9735.83760 a.u.^3 (  1442.70227 Ang^3 )

CELL_PARAMETERS (alat)
  24.058294126  -0.002192356   0.000000000
  -0.001341739   6.509292054   0.000000000
   0.000000000   0.000000000   9.212515550

ATOMIC_POSITIONS (angstrom)
C      -11.335280905  -3.515203132   0.000000000
C      -10.657767548  -1.149649613   0.000000000
C      -12.033031163  -7.107759788   0.000000000
C      -12.031326615  -5.724096322   0.000000000
C      -10.944247190  -4.869160124   0.000000000
C      -10.338808038  -2.534974709   0.000000000
C       -8.985760316  -3.012717974   0.000000000
C       -8.192434693  -0.717181304   0.000000000
C       -9.526336004  -6.767499680   0.000000000
C       -9.682866449  -5.356879517   0.000000000
C       -8.653891794  -4.400804217   0.000000000
C       -7.911461714  -2.099192195   0.000000000
C       -6.578108913  -2.564323810   0.000000000
C       -5.806387518  -0.245896701   0.000000000
C       -7.125796276  -6.285858068   0.000000000
C       -7.349229181  -4.878790195   0.000000000
C       -6.284145613  -3.951282991   0.000000000
C       -5.517574956  -1.633184889   0.000000000
C       -4.178728834  -2.099522550   0.000000000
C       -3.424138062   0.202618721   0.000000000
C       -4.737058424  -5.828536905   0.000000000
C       -4.961882542  -4.420577505   0.000000000
C       -3.892737039  -3.482790455   0.000000000
C       -3.097430525  -1.187683989   0.000000000
C       -1.730699233  -1.658846422   0.000000000
C       -1.110502040   0.680446865   0.000000000
C       -2.384811748  -5.350149373   0.000000000
C       -2.546600674  -3.937650826   0.000000000
C       -1.403364997  -3.046551554   0.000000000
C       -0.715541301  -0.676400470   0.000000000
C        0.713170432  -0.676470962   0.000000000
C        1.105099243   0.680029519   0.000000000
C       -0.000673053  -4.977164160   0.000000000
C       -0.000879723  -3.593109373   0.000000000
C        1.399998538  -3.046541966   0.000000000
C        1.726158571  -1.659274114   0.000000000
C        3.088907501  -1.187830369   0.000000000
C        3.413577242   0.201583523   0.000000000
C        2.380884236  -5.349818198   0.000000000
C        2.540180472  -3.938378442   0.000000000
C        3.883120559  -3.483612146   0.000000000
C        4.167810371  -2.100500424   0.000000000
C        5.503697730  -1.632252402   0.000000000
C        5.791361812  -0.246027847   0.000000000
C        4.726465742  -5.828725203   0.000000000
C        4.951407014  -4.420956882   0.000000000
C        6.271404898  -3.950299333   0.000000000
C        6.560859752  -2.564412490   0.000000000
C        7.893877259  -2.094718931   0.000000000
C        8.175441759  -0.716749156   0.000000000
C        7.113957767  -6.283092448   0.000000000
C        7.335009264  -4.876554488   0.000000000
C        8.641907380  -4.398668976   0.000000000
C        8.967995800  -3.009028351   0.000000000
C       10.322227945  -2.532973131   0.000000000
C       10.649883277  -1.152489915   0.000000000
C        9.516365619  -6.770006826   0.000000000
C        9.671733891  -5.358446514   0.000000000
C       10.927903455  -4.877297400   0.000000000
C       11.314745281  -3.523759121   0.000000000



     Writing output data file GB mgraphene.save
     Check: negative starting charge=   -0.000302
     NEW-OLD atomic charge density approx. for the potential
     NEW k-points:
        k(    1) = (   0.0000000   0.0000000   0.0000000), wk =   0.5000000
        k(    2) = (  -0.0000070  -0.0768133   0.0000000), wk =   0.5000000
        k(    3) = (  -0.0207829  -0.0000043   0.0000000), wk =   0.5000000
        k(    4) = (  -0.0207899  -0.0768176   0.0000000), wk =   0.5000000

     Check: negative/imaginary core charge=   -0.000022    0.000000
     Check: negative starting charge=   -0.000104

     negative rho (up, down):  0.901E-03 0.000E+00
     extrapolated charge  234.99577, renormalised to  240.00000

     total cpu time spent up to now is 825113.33 secs

     per-process dynamical memory:   591.4 Mb

     Self-consistent Calculation

     iteration #  1     ecut=    37.00 Ry     beta=0.30
     Davidson diagonalization with overlap
     c_bands:  2 eigenvalues not converged
     c_bands:  5 eigenvalues not converged
     ethr =  1.00E-06,  avg # of iterations = 17.5

     negative rho (up, down):  0.864E-03 0.000E+00

     total cpu time spent up to now is 836679.69 secs

     total energy              =   -1068.09001313 Ry
     Harris-Foulkes estimate   =   -1115.18009924 Ry
     estimated scf accuracy    <       0.12699097 Ry

     iteration #  2     ecut=    37.00 Ry     beta=0.30
     Davidson diagonalization with overlap
     c_bands:  3 eigenvalues not converged
     c_bands:  2 eigenvalues not converged
     ethr =  5.29E-05,  avg # of iterations = 12.5

     negative rho (up, down):  0.805E-03 0.000E+00

     total cpu time spent up to now is 843376.19 secs

     total energy              =   -1068.32156427 Ry
     Harris-Foulkes estimate   =   -1068.33514014 Ry
     estimated scf accuracy    <       0.04931700 Ry

     iteration #  3     ecut=    37.00 Ry     beta=0.30
     Davidson diagonalization with overlap
     c_bands:  1 eigenvalues not converged
     ethr =  2.05E-05,  avg # of iterations =  9.5

     negative rho (up, down):  0.771E-03 0.000E+00

     total cpu time spent up to now is 846460.78 secs

     total energy              =   -1068.31941742 Ry
     Harris-Foulkes estimate   =   -1068.32369757 Ry
     estimated scf accuracy    <       0.02098853 Ry

     iteration #  4     ecut=    37.00 Ry     beta=0.30
 		 	   		  
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