NLPP derivatives in optimization need SoA

[jtkrogel]

Currently only supported in AoS.

[jtkrogel]

It turns out that NLPP derivatives are sometimes crucial for correct optimization. Below is a comparison plot of the change in the total energy for Li2 during Jastrow optimization with and without the NLPP derivatives on.

For work on forces, we will have to use the AoS code for optimization until SoA is fixed for this.

[jtkrogel]

Who is looking into fixing this issue?

[ye-luo]

OK. I will take care of it next week.

[prckent]

Still investigating, but I think another user might have been caught by this for a heavier system.
Since SoA is the default, it means that new users will have worse wavefunction optimization than they should. Once implemented, I think we should make sure that NLPP derivatives are on by default in all examples, change the code default etc. Better to be slower but reliable.

[jtkrogel]

I agree 100% that these should be on by default.

[ye-luo]

1. This feature should be default.
2. implementing optimized virtual move code path is necessary to have painless 1.