[Pw_forum] help

[Anik Shrivastava]

Dear all
The program mentioned below is for heating and quenching of cooling, i have
some question regarding this, please tell me what mistake am i doing.

1This system doesn't quench and show higher temperature at the end,say
initial temp is 1600K and, End temperature is around 6000K, when is using
'reduced-T' ,and around 2500K when berendsen is used, except these two, if
i use any different way i.e rescaling etc. then system would not be
converge,

*why?*
2.If i choose deltaT and nraise less than 400 and 20 respectively then
system doesn't converge ????


Thanks in advance



&control
calculation='md'
restart_mode='from_scratch',
prefix = 'Si'
pseudo_dir = '/home/metal/Desktop/espresso-5.0.2/pseudo',
outdir='./',
dt=10,
nstep=500,
disk_io='high'
/
&system
ibrav= 1, celldm(1)=10.18, nat= 8, ntyp= 1,
ecutwfc = 35.0, nosym=.true.
/
&electrons
conv_thr = 1.0d-8,
mixing_beta = 0.7

/
&ions
ion_dynamics='verlet'
pot_extrapolation='second-order'
wfc_extrapolation='second-order'
ion_temperature='reduce-T'
tempw=1600.D0
delta_t=-400.D0
nraise=20

/
ATOMIC_SPECIES
Si 28.086 Si.pz-vbc.UPF

Si -0.123 -0.123 -0.123
Si 0.377 0.377 -0.123
Si 0.377 -0.123 0.377
Si -0.123 0.377 0.377
Si 0.123 0.123 0.123
Si 0.623 0.623 0.123
Si 0.623 0.123 0.623
Si 0.123 0.623 0.623
K_POINTS {automatic}
1 1 1 0 0 0



Anik shrivastava
Senior Research Fellow
Naval Materials Research Lab,DRDO
Mumbai-400085
India
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