Practical Aspects of DDA Simulations

Then the total polarization of the subvolume can be evaluated as follows  

The susceptibility of the boundary subvolume is replaced by an effective one. The effective self-term is evaluated directly starting from Eq. (2.7), considering x and E constant inside each part  

Filler [116] evaluated the integrals in Eq. (2.78) numerically. The polarizability is obtained from Eq. (2.22) using and iFl yf, while Eq. (2.19) remains unchanged. Hence, the WD does not modify the general numerical scheme. A significant improvement of DDA accuracy due to the WD was shown both by theoretical analysis [104] and in sample simulations [103,116]. 

Two other improvements are not aimed exclusively at shape errors, but they affect only dipoles close to the boundary. The first one is the RGB formulation discussed in Sec. 2.4.S.2. Second one is the spectral filtering of x that was proposed in combination with the FCD [102] to smooth the change of x at the particle boundary by removing high-frequency components. 

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