[Pw_forum] Surface Phonon and vib. of molecule

[ashima]

Stefano Baroni <baroni at sissa.it> wrote:

> 
> On Jul 17, 2004, at 1:08 PM, ashima wrote:

> as a first approximation, the computer does not know the difference 
> between a "slab" and a "crystal". A "slab" is simply a crystal with 
> lots of empty space stuffed into it. So, just set the supercell and 
> calculate its vibrational modes "as though" it were a physical crystal. 
> Of course, the number of modes thus obtained is limited by the 
> thickness of the slab. When you're done with this excercise, please 
> revert to this forum and we will teach you how to simulate a 
> "semi-infinite" slab by patching interatomic force constants calculated 
> for the bulk onto the results obtained for the finite slab.
> 

Thank you for your advise.
I will charange the calculations in the way you told.

Best regards,
H. Ashima

*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/
Hidenori Ashima

Catalysis Research Center
Hokkaido University

e-mail : ashima at cat.hokudai.ac.jp
*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/