[CP2K-user] [CP2K:18026] dipole moment of optimized water

[Rajendra Maharjan]

Making the box size very large (whether periodic cell or non-periodic), 
converges the dipole moment of water that is ~1.957 D using PBE/TZV2P-GTH 
method/basis set. Also, I did just single point calculation on the 
optimized water, that also match ~1.96 D water dipole moment.
Is this fine doing these methods to find gas phase water dipole moment?
Thank You very much.

Sincerely,
Rajendra Maharjan
On Monday, November 14, 2022 at 8:35:44 AM UTC-6 Rajendra Maharjan wrote:

> Dear Professor,
> I did geometry optimization of only a single water molecule to find its 
> gas phase dipole moment using PBE/GTH-TZV2P method/basis set. I also did 
> gas phase geometry optimization by turning off the cell pbc, but still I 
> calculate different dipole moment of water. I also distorted the water 
> molecule structure and the final optimized structure is fine with O-H 
> covalent bond length of 0.97Å and 103.9° HOH bond angle. However, the 
> dipole moment keep on changing if we change the cell size and also the 
> water configuration.
> I need the exact gas phase dipole moment of water using PBE/GTH-TZV2P for 
> calculating its dipole moment in condensed phase.
> Could you please help me how can I get accurate gas phase dipole moment of 
> optimized water?
> Thank You very much Professor for you reply.
> Please find attached my input file to find out optimized water dipole 
> moment.
>
> Sincerely,
> Rajendra Maharjan
>
> On Monday, November 14, 2022 at 5:02:49 AM UTC-6 jgh wrote:
>
>> Hi 
>>
>> two possibilities: 
>> 1) if you are doing periodic calculations, you have dipole-dipole 
>> interactions that 
>> are cell dependent and lead to a very slow convergence of the local 
>> dipole. 
>> 2) If you check the cell dipole in the output file, you get 
>> polarization/cell volume. 
>>
>> regards 
>> JH 
>>
>> ________________________________________ 
>> From: cp... at googlegroups.com <cp... at googlegroups.com> on behalf of 
>> Rajendra Maharjan <ryandra... at gmail.com> 
>> Sent: Monday, November 14, 2022 1:00 AM 
>> To: cp2k 
>> Subject: [CP2K:18018] dipole moment of optimized water 
>>
>> Greetings, 
>> I did geometric optimization of water molecule to find out its dipole 
>> moment. However, on changing the cell size under 'ABC' and also the water 
>> configuration, I am constantly getting different dipole moment. Does the 
>> dipole moment of optimized water depend on cell size and water 
>> configuration? I think the dipole moment should be the same regardless of 
>> cell size and water configuration after geometry optimization. 
>> Note: I used Barry phase formula for calculating dipole moment with 
>> 'PERIODIC=T' 
>> Thank You 
>>
>>
>>
>> -- 
>> You received this message because you are subscribed to the Google Groups 
>> "cp2k" group. 
>> To unsubscribe from this group and stop receiving emails from it, send an 
>> email to cp2k+uns... at googlegroups.com<mailto:cp2k+uns... at googlegroups.com>. 
>>
>> To view this discussion on the web visit 
>> https://groups.google.com/d/msgid/cp2k/c4c6148a-bfac-41e2-8f61-50453e4c8667n%40googlegroups.com
>> <
>> https://groups.google.com/d/msgid/cp2k/c4c6148a-bfac-41e2-8f61-50453e4c8667n%40googlegroups.com?utm_medium=email&utm_source=footer>. 
>>
>>
>

-- 
You received this message because you are subscribed to the Google Groups "cp2k" group.
To unsubscribe from this group and stop receiving emails from it, send an email to cp2k+unsubscribe at googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/cp2k/5d9f9815-dd28-46af-99af-20d8177ec7d8n%40googlegroups.com.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20221114/2dcb33de/attachment.htm>