Ceilidh ... Re^2: FIREFLY based comments on speeds and accuracies of SBKJC vs 6-31G?

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Re^2: FIREFLY based comments on speeds and accuracies of SBKJC vs 6-31G?

Dear Alex,
Thats an important information. Thanks again. Alex could you comment on their speeds? Logically if they reduce the no. of basis functions, then they should be really fast. I want to be sure about their speeds before using them. It would be good if you could compare their speeds with the 6-31G and its variants.

Regards,

On Fri Apr 18 '14 9:10pm, Alex Granovsky wrote
----------------------------------------------
>Dear Siddheshwar,

>for second row elements ECPs are computationally inefficient as
>they remove only single orbital (i.e. 1s) per atom. If you use
>SBK, you still need to add polarization function(s) to get
>reasonable results. SBK basis for Li, Be, B, C, N, O, and F
>atoms has only two L-type (i.e. combined S and P) shells for
>valence electrons and thus it is (approximately) a DZV-quality
>basis set.

>Kind regards,
>Alex Granovsky
>
>
>On Tue Apr 15 '14 1:24pm, Siddheshwar Chopra wrote
>--------------------------------------------------
>>Dear All,
>>This is the first time I am using SBKJC ECPs for the same samples for which I used 6-31G basis sets. Could anyone point out their speed and accuracy comparisons (Firefly based)? As per Jensen's book I read that for the second row elements, SBKJC gives almost same error as that of TZP. And I have never used TZPs. I have till now worked with only 6-31G and variants.

>>Regards,

Sat Apr 19 '14 6:32pm

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