[Pw_forum] about vc-relax of graphite

[Detlef Schmicker]

Hello NiuLi,

I had simelar problems. I reduced dt, and it worked.

Detlef

Am Montag, den 05.03.2007, 20:01 +0800 schrieb li niu:
> dear all:
> When optimizing lattice constant of the bulk graphite I met an error :
> ---------------------------------------------------
> from checkallsym : error #         3
>      not orthogonal operation
> ---------------------------------------------------
> What is the reason? How to resolve it?
> any help will be appreciated
> NiuLi
> =================================================
> 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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