[CP2K-user] Extremely slow SCF convergence on O2/metal

[fa...@gmail.com]

Dear You,

The wavelet solver is supported by version 6. But the manual states:
"[...] *and slab-boundary conditions (but only PERIODIC XZ)*. [...]"
You might have to rotate your system to accomodate this restriction.

Best,
Fabian
On Saturday, 14 November 2020 at 04:50:57 UTC+1 Y Lu wrote:

> Dear Fabian,
>
> yes it works like a charm! Amazing!
>
> I was running CP2K 6 and it didn't support WAVELET Poisson solver on 2D 
> but I'll try 7 instead.
>
> Thanks a lot!
>
> Best regards,
>
> You
>
>
>
> On Friday, 13 November 2020 at 17:13:49 UTC fa... at gmail.com wrote:
>
>> Dear You,
>>
>> A few pointer that can improve the scf convergence:
>>  - decrease EPS_DEFAULT to at least 1e-12
>>  - increase the smearing temperature
>>  - increase the cutoff, 300 is rather low here
>>  - use BROYDEN_MIXING
>>  - I found that ALPHA between 0.15 and 0.2 is often a good choice for 
>> metallic systems
>>  - you can use far fewer ADDED_MOS, 20 is plenty here
>>
>> Another issue you should address is the periodicity. The settings in 
>> &POISSON and &CELL have to match unless you really know what you are doing. 
>> The WAVELET solver allows for slab periodicity, see 
>> https://manual.cp2k.org/cp2k-7_1-branch/CP2K_INPUT/FORCE_EVAL/DFT/POISSON/WAVELET.html
>> .
>>
>> The attached input (ignoring the problem with the periodicity) converged 
>> within 120 iterations. This can probably still be improved upon.
>>
>> Cheers,
>> Fabian
>>
>> On Friday, 13 November 2020 at 17:15:05 UTC+1 Y Lu wrote:
>>
>>> Google didn't allow to post with plain text attachments!
>>>
>>>
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