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Monoclinic Crystal Structure

Posted: Thu Jul 08, 2010 2:55 pm
by apple
hi all,
would you please share with me what is the best way of optimizing a monoclinic structure. Thank you in advance,

apple

Monoclinic Crystal Structure

Posted: Thu Jul 08, 2010 7:16 pm
by forsdan
Given that you have some reasonable starting guess for the volume, angles and the basis vectors I would either

1) Set ISIF = 4 and perform calculations for different volumes.

or

2) Increase the ENCUT and set PREC = Accurate and relax the structure with ISIF = 3.

The increased accuracy in option 2 is required to eliminate/reduce the Pulay stresses when the cell is relaxed, please see

http://cms.mpi.univie.ac.at/vasp/vasp/V ... tress.html

For more information on why option 1 is an alternative to option 2, please look at

http://cms.mpi.univie.ac.at/vasp/vasp/A ... s_two.html

Cheers,
/Dan

<span class='smallblacktext'>[ Edited Thu Jul 08 2010, 09:18PM ]</span>

Monoclinic Crystal Structure

Posted: Sun Jul 11, 2010 4:54 pm
by apple
Thank you.