[CP2K-user] Solid state DFT and vibrational analysis

[bobs your uncle]

Hi folks,

Just a general question regarding vibrational analysis in an organic 
crystal using CP2K (just solid state DFT ignoring AIMD for now).
I thought about using more specialized software like quantum espresso - 
although I would prefer to use Crystal which I don't have access to 
currently - but the possibility of using CP2K for both solid state DFT, and 
later AIMD was more appealing to me for obvious reasons.
So first off, would you recommend CP2K for vibrational analysis of periodic 
systems? It would seem to me that it is uncommon, as I am having issues 
finding examples in the literature, and there aren't any guides either.

To get to grips with CP2K, I first completed some of the tutorials as 
recommended before moving onto a "toy" system, where I have been attempting 
to reinvent the wheel with vibrational analysis. 
Of course, I would really like to know if anyone could advise me on the 
"right" way to do this. 
Currently, I start with a cell optimisation on an experimental crystal 
structure - following the sodium chloride guide on the CP2K website - then 
reoptimize the geometry with tighter convergence threshholds etc. 
I take that geometry and perform a vibrational analysis, and have succeeded 
in producing a complete set of real harmonics this way - which is a start - 
but I haven't been able to simulate some of the low frequency "terahertz" 
modes that have been reproduced in the literature (although for my system, 
the papers I can find don't talk at all about the software or process 
followed).
No one in my immediate academic circle is trained in these calculations, so 
I would really appreciate some of your wisdom if you could share it!

Sorry, that was a bit of a read, but I'll put input files up if you are 
interested.

Cheers
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20190429/0906db12/attachment.htm>