Firefly and PC GAMESS-related discussion club

 
Learn how to ask questions correctly  
 
 

 

Slawomir Janicki
slawomir.janicki@comcast.net

Thanks for the feedback on cc-pV(5-h)Z. It looks like I would need to test it before making any commitments.

Your experience with pc-4 is interesting. I am not very happy with the entire pc-x family of basis sets either. They seem to converge slower to the CBS limit than cc-pVxZ or xZVPD and HF calculations with the augmented sets are nearly impossible to converge beyond aug-pc-2.

All the best,
Slawomir


On Thu Nov 28 '13 10:36pm, Thomas Pijper wrote
----------------------------------------------
>Hi Slawomir,

>My experience with cc-pV(5-h)Z is limited, but in the cases where I have used it I found it always yields energies and geometries closer to the complete basis set than cc-pVQZ. On the other hand, I found its use limited due to the amount of basis functions involved, even with h functions removed.

>Experience with the full cc-pV5Z sets I do not have. I recall Frank Jensen writing that high angular momentum functions are important for recovering electron correlation in post-Hartree-Fock methods, so it might perform well with those. If someone has used these sets I too would like to learn about their experiences.

>By the way, I've on occasion used pc-4 with h functions removed. I found it to behave erratically in its convergence towards the CBS, though this is based on a very small amount of results.
>
>
>Kind regards,
>Thom
>
>
>
>On Thu Nov 28 '13 7:53pm, Slawomir Janicki wrote
>------------------------------------------------
>>Does anyone have any experience using cc-pV5Z without h-functions for 2nd row elements? I was thinking about putting together a Firefly basis set library like that.

>>Apparently GAMESS-US was ignoring the h-functions until release 2013R1 rather than stopping like Firefly. I wonder how do the results compare to the full cc-pV5Z basis set.

>>Going to check the turkey in the oven...

>>Cheers,
>>Slawomir