Why I get a 5000 cm-1 vibration frequency for single H2 molecule?
jingyu... at gmail.com
Thu Dec 4 22:22:07 UTC 2014
Thanks very much. I checked the data in cccbdb. It really depends on the
basis set. I have a another question and hope you have some idea. Why did
only get 3 vibration modes for CO2 ? The degenerate modes around 600 cm-1
should have two but only shows one in my output. And I still checked the
cccbdb data base. There are 3 frequency modes for CO2 molecule shown in the
table. And in the full list, there indeed has 4 modes. I also got 3 modes
for CO2 before when I used VASP.
Another question: In the .mol file of single CO2 frequency calculation, I
only got 3 modes which no rotation or translation modes. But when I put the
CO2 in porous material to study the adsorption property, the .mol file has
the rotation and translation modes for CO2. I just want to know how does
this happen? I remember Alex mentioned in previous posts that the CP2K
output will automatically purify the R and T modes. If this is true, how
does the R and T modes shows in the outputs for CO2 in porous material but
don't show for single CO2 molecule. (Note: all the input files are same
with my post one.)
Thanks very much for your help!
On Thursday, December 4, 2014 5:31:37 AM UTC-5, Florian Schiffmann wrote:
> looking at cccbdb, you can see that using a bad basis can have a miserable
> effect. In your case a DZVP-SR basis has the same effect, remove if you use
> the normal DZVP optimize and run the analysis you will get a pretty nice
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