I 2 basis sets, for which one is DFT calc faster?

[AJ007]

Hello fellow physicist,
I'm new on this subject, I hope that you can help me clear some stuff out.

If I have 2 basis sets; A containing 100 basis functions and B containing 50 basis functions, for which one of them will a DFT calculation be faster?
Also, is a DFT calculation using basis sets A, more accurate than if it uses B?

Very thankful,
Best regards
AJ

 

[Ben Wilson]

Hello fellow physicist,
I'm new on this subject, I hope that you can help me clear some stuff out.

If I have 2 basis sets; A containing 100 basis functions and B containing 50 basis functions, for which one of them will a DFT calculation be faster?
Also, is a DFT calculation using basis sets A, more accurate than if it uses B?

Very thankful,
Best regards
AJ

Generally speaking, B would be faster, A would be more precise (lower energies). This is because your completing more calculations for the extra basis functions, but the density in A would be more realistic.

 

[Gogo]

As Ben said, "Generally speaking" B would be faster. However, it should be noted that accuracy of a certain basis set truly depends on the system (molecule) you are dealing with. A larger basis set may not necessarily give more accurate results. You need to do your own tests of basis sets or look up references from journal aritcles. I would suggest looking up works by Don Truhlar from U Minnesota - he must have something out there.