[CP2K-user] [CP2K:12777] Negative frequencies in vibrational analysis

Lucas Lodeiro eluni... at gmail.com
Thu Jan 16 15:30:58 UTC 2020

Hi Sumit,
If a vibrational mode presents a "negative" frequency (really it is an
imaginary frequency, due to the hessian element is the negative one), it is
because your system is not at minimmum stationary point (it could be in a
1° order saddle point). To fix it you must to do a geometry optimization
first, to reach a stationary point, then a vibrational analysis will have
useful information.
It is important to note that a vibrational analysis with Harmonic
approximation does not have sense if you do not found a stationary point on
the Potential Energy Surface.

Regards - Lucas Lodeiro

El mar., 14 ene. 2020 a las 9:23, sumit agrawal (<sumitag... at gmail.com>)

> When I am trying to do to vibrational analysis, there are some modes that
> have negative frequencies. How can I solve this issue?
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