Hi all,

For low dimensional systems there is an options CUTBox to apply the box coulomb cutoff for faster convergence.

From wiki and tutorial, for 2D monolayer BN the CUTBox is selected to be (c - 1), e.g. CUTBox z = 32Bohr for a 33Bohr cell along z-axis.

I wonder how to select CUTBox for a 2D system with thickness, for example a bilayer BN. Assume the 2D system is 4 Bohr thick and the cell z is 30Bohr, what is best CUTBox?

From my tests the BSE eps fluctuates a lot from CUTBox 15 to 25 (30 cell - 4 thickness - 1 padding ) Bohr. As all of these are indeed larger than 2*thickness, I don't quite understand why results is sensitive to CUTBox and what is the CUTBox should be used here.

Thanks!

Best,

Feng