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<div class="moz-cite-prefix">if you are performing a microcanonical
MD simulation the total energy is conserved but not the kinetic
energy that is related to the instantaneous temperature.<br>
kinetic energy fluctuates around an average value. the larger the
number of atoms the smaller should be temperature fluctuation.<br>
<br>
stefano <br>
<br>
On 02/19/2013 08:12 PM, dev pe wrote:<br>
</div>
<blockquote
cite="mid:CAG1HzpEu4uZ1L+bw0eR77wAtL58mvgXRYqbn_qXsAoY5ZVrhqA@mail.gmail.com"
type="cite">
<pre wrap="">Dear QE users
I am trying to model amorphous Si using heat-and-quench by BO molecular
dynamics (based on example3). My starting temperature is 1600K. But, In my
output file, after every step, I see a different instantaneous temperature
printed. Why is that so? Am I missing any input parameter? My input file is
as given below:
&control
calculation='md'
restart_mode='from_scratch',
prefix = 'Si'
pseudo_dir = '/home/deva/espresso-5.0.1/pseudo/',
outdir='./',
dt=20,
nstep=60,
disk_io='high'
/
&system
ibrav= 1, celldm(1)=10.18, nat= 8, ntyp= 1,
ecutwfc = 20.0, 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
ATOMIC_POSITIONS
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
Thanks in advance
Devan
PhD student
UMD
College Park
</pre>
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