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Dear all.<br>
<br>
I am trying to calculate electric dipole moments of an isolated
water molecule through Wannier functions (Wannier90 and QE).
Basically, I want to reproduce the results on Silvestrelli &
Parrinello, 1999 - J Chem Phys. Their computations were performed at
the Gamma point only of the Brillouin zone, with a plane-wave cutoff
of 70 Ry and a BLYP density functional. The monomer was optimized in
a cubic supercell of side 10.6 Å. They found a dipole moment of
1.87 D.<br>
<br>
I used the same description in two simulations. However, in one of
them, the water molecule were translated by 5.0 Å at z-direction in
the beginning of the computations. That is the only difference
between the simulations. I provide the inputs and the main results
attached to the e-mail. My WF calculations followed steps below:<br>
<br>
<big><small>1) pw.x < h2o.relax > relax.out<br>
</small></big><big><small>2) pw.x < h2o.nscf > nscf.out<br>
3) wannier90.x -pp h2o <br>
4) pw2wannier90.x < h2o.pw2wan > pw2wan.out <br>
5) wannier90.x h2o<br>
<br>
In the centered-molecule simulation, I found 1.8559 D, which I
can say this value agrees with the paper one. While, in the
translated-molecule simulation, I found 103.4 D.<br>
The difference is enormous for two very similar simulations. I
cannot explain so great difference due to a translation that is
lesser than the supercell side. <br>
<br>
I would be pleased if someone could confirm my results. The
attached files with the characters '_tr' are of the
translated-molecule simulation. <br>
<br>
Cheers,<br>
<br>
Pedro Moreira<br>
<br>
--------------------------------<br>
IFGW - Unicamp - Brazil<br>
</small></big> <br>
<br>
<br>
<br>
<br>
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