Add support for the r2SCAN+rVV10 functional

[SyntaxSmith]

Background

The r2SCAN functional is a revised version of the SCAN functional, offering improved numerical stability and computational efficiency while maintaining high accuracy. The rVV10 method is a robust non-local correction for van der Waals (vdW) interactions.

The absence of the r2SCAN+rVV10 combination limits the application of ABACUS in systems where an accurate description of vdW interactions is critical. This includes key research areas such as:

• Layered materials (e.g., graphene, transition metal dichalcogenides)
• Molecular crystals and organic semiconductors
• Surface adsorption and catalysis
• Biomolecular systems

Research in these fields often requires a versatile functional that can accurately describe covalent, metallic, and weak interactions simultaneously.
And there is a discussion about this request: https://github.com/deepmodeling/abacus-develop/discussions/5260

Describe the solution you'd like

I would like to request the formal integration of the r2SCAN+rVV10 functional combination into ABACUS.

Ideally, a user should be able to select it through the dft_functional parameter in the INPUT file, in a manner similar to how other vdW-corrected functionals are currently handled

[mohanchen]

Thanks for the advice! We will consider implement the functional when we can find a good developer.

[QuantumMisaka]

@mohanchen r2SCAN can be used now via LibXC, the only and major absence is rVV10 vdW correction.

[mohanchen]

@mohanchen r2SCAN can be used now via LibXC, the only and major absence is rVV10 vdW correction.

I see, we will try to implement it soon.

[mohanchen]

Thanks for your both suggestions. I will transfer the issue to discussion.