[CP2K-user] [CP2K:19081] Re: Visualization of negative frequencies

[Victor Volkov]

Good day, Rashmi.

Does VIBRATIONAL_ANALYSIS
employ the &GEO_OPT section (even if it is included in the input)
to run the structural optimization under the proper thresholds?

I am not sure.
I do not think so.

I run GEO_OPT as a devoted job prior
any vibrational analysis.

If you confirm optimization done according to the thresholds,
then, observing negative frequencies (upon the consequent vibrational
analysis)
would be a proper question to post to the developers.

Sincerely,
Victor




On Fri, Jul 7, 2023 at 10:03 AM 'RASHMI BRAHMA' via cp2k <
cp2k at googlegroups.com> wrote:

> Hello Victor
>
> Thank you for your suggestion. I have tried incorporating it in my input
> file, but I am still getting negative frequencies.
>
> On Thursday, June 29, 2023 at 12:27:29 PM UTC+5:30 Victor Volkov wrote:
>
>> Hello Rashmi.
>>
>> In the &GEO_OPT section, you have
>>     MAX_DR    1.0E-03
>>     MAX_FORCE 1.0E-03
>>     RMS_DR    1.0E-03
>>     RMS_FORCE 1.0E-03
>>
>> May be, you need
>>     MAX_DR    1.0E-06
>>     RMS_DR    1.0E-06
>>     MAX_FORCE 1.0E-07
>>     RMS_FORCE 1.0E-07
>> or even more demanding criteria.
>>
>> Victor
>>
>> On Thu, Jun 29, 2023 at 9:20 AM 'RASHMI BRAHMA' via cp2k <
>> cp... at googlegroups.com> wrote:
>>
>>> I have attached the input file and outfput files generated from it.
>>>
>>> On Wednesday, June 28, 2023 at 12:56:35 PM UTC+5:30 Victor Volkov wrote:
>>>
>>>> Hello, dear Rashmi.
>>>> I am not a developer of CP2K.
>>>>
>>>> First, may be, you need to search through previous communications on
>>>> the discussion group
>>>> (using keywords like "vibrations", "normal modes" etc) to study them
>>>> sorting what might be relevant or not.
>>>>
>>>> Second, I do not think anybody would be able to give you a clear answer
>>>> for your question
>>>> since setting a system and configuring various parameters is rather
>>>> demanding - you would need to
>>>> attach an input that somebody would try to approach.
>>>>
>>>> Third, the term you use "visualize" is not clear.
>>>> If you ask how to image atomic displacements about computed normal
>>>> modes,
>>>> this concerns using other software but not CP2K.
>>>> For example, it is possible to use molden.
>>>> (Sometimes, I program displacement images in Mathematica.)
>>>> Again, using "visualize" is not clear.
>>>>
>>>> I hope, these comments would help you to attract attention of the
>>>> developers.
>>>>
>>>> Victor
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> On Wed, Jun 28, 2023 at 10:06 AM 'RASHMI BRAHMA' via cp2k <
>>>> cp... at googlegroups.com> wrote:
>>>>
>>>>> Hello
>>>>>
>>>>> I am new to cp2k, and I keep getting negative frequencies even after
>>>>> optimization of the coordinates of my system. Can anyone help me how can i
>>>>> visualize those or remove those negative frequencies from my system? Please
>>>>> help me out.
>>>>>
>>>>> On Tuesday, June 27, 2023 at 7:57:35 PM UTC+5:30 RASHMI BRAHMA wrote:
>>>>>
>>>>>> Hello everyone
>>>>>>
>>>>>> Can anyone tell me where can I visualize negative frequencies that is
>>>>>> occurring in my system?
>>>>>>
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