Explain how the (useful!) _estimate_min_cpus was defined?

[superstar54]

The warning message related to calculator too big suggests “>= 100 cpus) this suggestion originates from max(100,estimate_min_cpus). Can you explain how the (useful!) _estimate_min_cpus was defined? Can we have a notebook or python script with the data, to be able to further discuss and refine over time?

[mikibonacci]

I added more details in the _estimate_min_cpus method, but basically I used parameters on number of atoms, volume, cpus, scf_cycles and time for a moderate relax run of SiO2, and then I found the power laws of the following formula

num_cpus = num_cpus0 * (n/n0)^3 * (v/v0)^(3/2) * (scf_cycles * t0)/tmax

using other simulations on SiO2, Silicon and Gold to find the power laws. This is very rough, and actually I plan to find a new more accurate model for this. So, I will produce soon a repository with more data and useful analysis.