[CP2K-user] GEO_OPT a molecular is 10000 time longer then gaussian

[Linfeng Gan]

Here is the result.


On Monday, May 18, 2020 at 8:41:45 AM UTC+8, Linfeng Gan wrote:
>
>
>  
>
>  
>
> Thank you for your advice, Travis.
>
> I had tested EPS_SCF from 1e-5 to 1e-14. I posted the 1e-5 one only 
> because it took the shortest time to get the final structure. And I will 
> try convergence criteria with 1e-4 as you suggest. 
>
>  
>
> Linfeng
>
>
> On Sunday, May 17, 2020 at 12:36:33 PM UTC+8, Travis wrote:
>>
>> Hi,
>>
>> I see you have EPS_SCF commented out in your input file. The default 
>> convergence threshold is 1e-5 au which is usually not tight enough for 
>> accurate forces (and certainly not for vibrational analysis, which is 
>> computed numerically - hence it will take ages over Gaussian). The value 
>> you commented out is actually better and may take less steps to converge. 
>> Your criteria for convergence are also extremely tight, 1e-4 au is 
>> typically enough. Also, just to be clear, CP2K when setup appropriately 
>> will reproduce Gaussian output for the total energies for non-periodic 
>> calculations. So you CAN use Gaussian for the gas phase reaction and CP2K 
>> for the surface reaction.
>>
>> -T
>>
>>
>> On Saturday, May 16, 2020 at 10:47:56 PM UTC-4, Linfeng Gan wrote:
>>>
>>>
>>> Thank you very much Vladimir,
>>>
>>> 1) I know CP2K is not a choice for small molecules. But I am 
>>> investigating an organic reaction which could take place in gas phase and 
>>> on C3N4 surface. I have to compare the data between the gas phase and the 
>>> surface. So, I can’t use gaussian or orca to that. DMol3 or CASTEP maybe is 
>>> best choice for me, but I think we should give open source software a 
>>> chance. So, CP2K is my choice right now. I am not very familiar with CP2K 
>>> that it’s why I go to this forum and ask for some help. 
>>>
>>> 2) Agree. 
>>>
>>> 3) Yes, it was. 
>>>
>>> 4) 10000 times is an exaggeration, I apologize for that. Form the same 
>>> initial structure, it took gaussian 41 seconds with a single Xeon 2680v2 
>>> CPU to finish the geometry optimization, but it took CP2k 40 minutes with 
>>> 20 CPU to do the same thing. If we include the frequencies calculation the 
>>> time is 4 minutes vs 71 minutesX20CPU. A single SCF calculation of CP2K was 
>>> pretty fast, but most of time was wasting in locating the minimize. 
>>> This efficiency issue only happened in this 1-butene molecular. Another 
>>> molecular I tested, cyclobutene, seemed much batter than 1-butene. 
>>>
>>> I attach all the input and the output file. So, you guy can help me to 
>>> improve this. Thanks all.
>>>
>>>
>>> Best,
>>> LInfeng
>>>
>>>
>>> On Friday, May 15, 2020 at 7:41:12 PM UTC+8, Vladimir Rybkin wrote:
>>>>
>>>> Dear Linfeng,
>>>>
>>>> a few general remarks:
>>>> 1) CP2K is not the most efficient tool for small molecules. For 
>>>> instance, it does a lot of integrations over cells in real and reciprocal 
>>>> space, and for a small molecule the cell is almost everywhere empty.
>>>> 2) CP2K does not use internal coordinates for optimisation. This has to 
>>>> do with the fact that it's mostly meant for large periodic systems. 
>>>> Gaussians' Berny algorithm does use internal coordinates and is very 
>>>> efficient for small systems.
>>>> 3) It's very likely that you 150 steps have not change the geometry 
>>>> significantly. 
>>>> 4) It's not completely clear where this 10000 times come from. It may 
>>>> have to do with how you compile and run your applications.
>>>>
>>>> That said, there's no specific problems with optimisers and efficiency. 
>>>> It's about applicability of tools for specific purposes. If you going to 
>>>> work with small molecules, you'd better stick to programs made for them, 
>>>> i.e. Gaussian. CP2K is meant for large and/or periodic systems.
>>>>
>>>> Yours,
>>>>
>>>> Vladimir
>>>>
>>>> пятница, 15 мая 2020 г., 2:51:51 UTC+2 пользователь Linfeng Gan написал:
>>>>>
>>>>> Hi all,
>>>>>
>>>>> When I optimized 1-butene molecular at B3lYP/6-311G** level, it took 
>>>>> much much longer than gaussian16 did.  I had test optimizer CG, BDGS 
>>>>> and LBFGD, nothing better. It seems the optimizers have some efficiency 
>>>>> issues. All three optimizer had taken at least 150 optimization steps to 
>>>>> get the final structure, but the initial structure had been optimized by 
>>>>> gaussian.   How could I improve that?
>>>>>
>>>>>  
>>>>>
>>>>> Best
>>>>>
>>>>> Linfeng
>>>>>
>>>>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20200518/3ff7335a/attachment.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: opt_geo.out
Type: application/octet-stream
Size: 757382 bytes
Desc: not available
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20200518/3ff7335a/attachment.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: opt_geo.inp
Type: chemical/x-gamess-input
Size: 3204 bytes
Desc: not available
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20200518/3ff7335a/attachment.inp>