# RGRID

### From FEFF

* Useful *

RGRID delta

The radial grid used for the potential and phase shift calculation is

, where δ = delta.

δ = 0.05 by default, which is sufficient for most cases. However, occasionally there are convergence problems in the atomic background at very high energies (the background curves upward) and in the phase shifts for very large atoms. If such convergence problems are encountered we suggest reducing δ to 0.03 or even 0.01. This will solve these problems at the cost of longer computation times (the time is proportional to 1 / δ). This option is also useful for testing and improving convergence of atomic background calculations.

* reduce grid for more accurate background at high energy RGRID 0.03