Error sensitivity study for side coupled muffin tin structures using a finite difference program

The sensitivity of three previously proposed side coupled standing wave muffin-tin structures are estimated using a finite difference program. The muffin tins consist of rectangular cavities only. Such geometries can be discretized by a program like MAFIA without errors. But as soon as small errors in the cavity dimensions are present, MAFIA is not able to discretize them with sufficient accuracy. Therefore a finite difference program adjusted to the problem has been written that discretizes the cavity volume exactly for all cavities where the position of two of the six cavity walls is perturbed. This program was used to calculate the shunt impedance of a big number of structures with random errors in the cavity dimensions