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# ML FF AFILT2 MB

ML_FF_AFILT2_MB = [real]
Default: ML_FF_AFILT2_MB = 0.002

Description: This tag sets the filtering parameter for the angular filtering for ML_FF_IAFILT2_MB in the machine learning force field method.

This tag is only used if ML_FF_LAFILT2_MB=.TRUE. and ML_FF_IAFILT2_MB=2 are used.

The angular filtering function[1] for ML_FF_IAFILT2_MB=2 is described as ${\displaystyle \eta _{{l,a_{{{\mathrm {FILT}}}}}}={\frac {1}{1+a_{{{\mathrm {FILT}}}}[l(l+1)]^{{2}}}}}$. The tag ML_FF_AFILT2_MB sets the parameter ${\displaystyle a_{{{\mathrm {FILT}}}}}$.

## References

1. [ J. P. Boyd, Chebyshev and Fourier Spectral Methods (Dover Publications, New York, 2000).]