[Pw_forum] Suitable pseudopotentials for LiH..H2O

[Prasenjit Ghosh]

Dear Savita,

I am not an expert on these type of systems.......however just a small piece
of advice.....a single molecule of water has a huge dipole moment.....so a
box size of 25 bohr may not be sufficient, until and unless binding to LiH
quenches the dipole moment......so you may like to check whether your box is
sufficiently big.....usually for a single molecule of water one uses about
35-40 bohr box or can use dipole correction.

Prasenjit

On 17 June 2011 11:42, <psavita at crlindia.com> wrote:

> Hello,
>
> I have been trying to get the optimum structure of LiH..H2O that has an
> intramolecular dihydrogen bond, using pwscf.
> I could get the proper structure earlier using mp2 theory and 6-31++g
> basis.
>
> For pwscf, the species is enclosed in a cubic box of 25 bohr for gamma
> point calculation.
> I tried the pz lda, pbe gga as well we blyp PS for the atoms in this
> system, however, the first and the last
> lead to H2O..LiH, the latter LiH being linear while pbe gives LiH + H2, but
> no dihydrogen bond. Is there any other PS
> that may lead to proper structure? Or is it that plane wave approach does
> not suit systems of this kind?
>
> Thanks in advance and best regards,
>
> Savita Pundlik
> Computational Materials Applied Research Group
> Computational Research Laboratories Ltd.,
> Taco House, Damle Path, Off Law College Road
> Pune - 411004, India.
>
>
>
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>


-- 
PRASENJIT GHOSH,
Assistant Professor,
IISER Pune,
First floor, Central Tower, Sai Trinity Building
Garware Circle, Sutarwadi, Pashan
Pune, Maharashtra 411021, India

Phone: +91 (20) 2590 8203
Fax: +91 (20) 2589 9790
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