[Pw_forum] vc-relax of graphite

[lan haiping]

Dear Niu Li,
 In your input file that diagonalization is 'cg',  but warnning information
is related to 'david' scheme.  I cannot understand it ..
   another suggestion to your input setting is about kpoints. i think 4x4
mesh grids are not enough for x-y plane, and you should set  more dense...


hope help

regards.

h.p





On 3/12/07, li niu <niuli1978 at yahoo.com.cn> wrote:
>
> dear Paolo,
>
> When I used a symmetry-conservin algorithm,  cell_dynamics = 'damp-w' ,
> I still met the same error :
> -------------------------------------------------------------------------
> from checkallsym : error #         3
>      not orthogonal operation
> ------------------------------------------------------------------------
> And when using  "nosym = .true.", I met a warning:
>      iteration #  1     ecut=    40.00 Ry     beta=0.70
>      Davidson diagonalization with overlap
>      WARNING:     2 eigenvalues not converged
>      WARNING:     2 eigenvalues not converged
>      WARNING:     2 eigenvalues not converged
>      WARNING:     2 eigenvalues not converged
>      WARNING:     2 eigenvalues not converged
>      WARNING:     1 eigenvalues not converged
>      WARNING:     1 eigenvalues not converged
>      WARNING:     2 eigenvalues not converged
>      WARNING:     2 eigenvalues not converged
>      WARNING:     2 eigenvalues not converged
>      WARNING:     2 eigenvalues not converged
>      WARNING:     2 eigenvalues not converged
>      WARNING:     1 eigenvalues not converged
>      WARNING:     2 eigenvalues not converged
>      WARNING:     2 eigenvalues not converged
>      WARNING:     1 eigenvalues not converged
>      WARNING:     2 eigenvalues not converged
>      WARNING:     1 eigenvalues not converged
>      WARNING:     1 eigenvalues not converged
>      WARNING:     2 eigenvalues not converged
>      WARNING:     1 eigenvalues not converged
>      WARNING:     2 eigenvalues not converged
>      WARNING:     2 eigenvalues not converged
>      WARNING:     1 eigenvalues not converged
>      WARNING:     2 eigenvalues not converged
>      WARNING:     2 eigenvalues not converged
>      WARNING:     2 eigenvalues not converged
>      WARNING:     2 eigenvalues not converged
>      ethr =  1.00E-06,  avg # of iterations = 19.8
>      negative rho (up, down):  0.381E-03 0.000E+00
>      total cpu time spent up to now is    626.96 secs
>      WARNING: integrated charge=    10.59801382, expected=    16.00000000
>
>  -----------------------------------------------------------------------------------------------
>      from electrons : error #         1
>      charge is wrong
>
>  -----------------------------------------------------------------------------------------------
>      stopping ...
>
> Now I don't know how to  optimize lattice constant of the bulk graphite.
> Please give me some help.thanks!
> Niu Li
> =====================================================
> My input as follows:
> cat > graphite.vcrx.in << EOF
> &CONTROL
>   calculation  = "vc-relax",
>   prefix       = "graphite",
>   pseudo_dir   = "$PSEUDO_DIR",
>   outdir       = "$TMP_DIR",
>   tstress = .true. ,
>   tprnfor = .true. ,
>                        nstep = 65 ,
>                etot_conv_thr = 1.0E-4 ,
>                forc_conv_thr = 1.0D-3 ,
>                           dt = 100 ,
> /
> &SYSTEM
>     ibrav = 4,
>     celldm(1) =4.6336,
>     celldm(3)=2.7243,
>     nat= 4, ntyp= 1,
>     ecutwfc =40
> /
> &ELECTRONS
>   diagonalization = 'cg',
>   conv_thr    = 1.D-9,
>   mixing_beta = 0.7D0,
> /
> &IONS
>   pot_extrapolation = "second_order",
>   wfc_extrapolation = "second_order",
> /
> &CELL
>                cell_dynamics = 'damp-w',
>                        press = 0.0 ,
>                        wmass = 0.010 ,
>  /
> ATOMIC_SPECIES
>  C   12.0107  C.pz-vbc.UPF
> ATOMIC_POSITIONS {crystal}
>  C  0.0000000 0.0000000 0.0000000
>  C  0.0000000 0.0000000 0.5000000
>  C  0.6666667 0.3333333 0.0000000
>  C  0.3333333 0.6666667 0.5000000
> K_POINTS automatic
> 4 4 4 1 1 1
> EOF
> $ECHO " optimizing the lattice constant for bulk graphite...\c"
> $PW_COMMAND < graphite.vcrx.in > graphite.vcrx.out
> $ECHO " done"
> ================================================================
>
>
> ------------------------------
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>


-- 
Hai-Ping Lan
Department of Electronics ,
Peking University , Bejing, 100871
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