Huckel basis set

[yasheng]

Hi All,

I have a question about Huckel basis set. is it ok to mix different Huckel basis sets in one calculation? for example, If I have copper and oxygen in my system, can I use Cerda.Copper and Muller.Oxygen ?

Thanks,
Yasheng

[zh]

It isn't a good idea to mix them because their parameters values were optimized by means of different strategies.

[Petr Khomyakov]

Technically, you can do it, but you have to clearly understand the reason why you want to do it, and verify if this basis set mixing gives any meaningful results for physical quantities calculated in your particular study.

[yasheng]

Thanks for your reply.

 For oxygen, only Hoffmann.Oxygen Huckel Basis set available. If we want to do calculations for oxides, we are restrained to use Hoffmann basis sets only, if we cannot mix different basis sets.

In my experience, Hoffman basis sets are giving wrong band gap. (I mean totally unreasonable)

[zh]

In principles, we can optimize the parameter values in the Huckel basis set by using the DFT calculated band structure and DOS of bulk materials as references.

Please see :
http://pubs.rsc.org/en/content/articlelanding/2012/dt/c2dt30298e#!divAbstract