Basis set superposition error - Part 2

[iopenshell]

Well, BSSE is often not too large, given the basis sets we use nowadays, and it would be a much smaller correction, relative to the bond energy in covalent systems. A lot of people skip it even in van der Waals complexes, unless they shoot for quantitatively (well, sometimes qualitative too) accurate results. It is quite easy to estimate though, so whenever in doubt, you can just check it real quick.

[cyberfrogITA]

Ok, thank you for yours suggests, you're very kind and helpful!

I think I'll evaluate the CP correction for one sistem, and if it's very small I'll skip it for the others.

[cyberfrogITA]

Many thanks for the answere!

I would ask you one more thing: I read that bsse is significant in the case of complex and Wan der Waals interaction. I'm investigating theoretically the de-hydrogenation of SiH nanotubes.

Pratically, a silicon nanotube with fully coverage of H atoms in which a H2 molecule go away.

This is the case of covalent bonds, do you think I have to evaluate the CP correction?

[iopenshell]

Yes, it is the same thing. If you imagine a potential energy curve for A+B->AB, that curve would be the same for AB->A+B. In both cases we use two points on this curve: one corresponds to the geometry of the complex, the other corresponds to the monomers at large (i.e., infinite) separation.

[cyberfrogITA]

How to deal with the opposite process? I mean in the case of

AB ---> A + B ?

Is the CP corretion the same that in the case described here?