Density mesh cut-off for mgga

[krahil]

Hello,
I had analysed optical spectrum for phosphorene using mgga with two different values of density mesh cut-off (60 and 90 hartree) keeping all other values same for both the cases. The results had huge difference.
What value should we keep for cut-off for the optimum results and how do we decide for it?

[Petr Khomyakov]

Typically, one should converge a given quantity with respect to computational settings, in this case with respect to density mesh cut off, i.e., you may want to increase it even more until you see that the change is within what you consider as a small effect.