[Pw_forum] metal optimization tricks and constraining atomic position in a slab
davidfoster751 at yahoo.com
Thu Apr 10 19:46:20 CEST 2014
Dear Users and supporters
"....Thank you for your quick answers...."
I have two questions:
1- I prepared 3*3*3 bulk Pd super cell, and used "vc-relax". The relaxation needed
more than 200 iteration. I finally relaxed it with restarting command. Please help
me in setting following parameters for fast relaxation for metals:
a- degauss (I think increasing it helps for fast coarse optimization, but after it
needs more fine optimization.
with increasing it, does it need more "nbnd"?)
b-mixing beta ( in my calculation, I set it to 0.3, but I got very fluctuation in optimization.
does increasing it helps optimization speed?)
c- I prepared input by a program that saves the structure in cif format. I used the coordination
with "crystal" card. is it true?
2- I prepared 5 layers Pd slab and should fix two layers' coordination, but I don't know how.
I read input style help but confused.
Ph.D. Student of Chemistry
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