The S02 card specifies the amplitude reduction factor . If the entry for is less than 0.1, then the value of is estimated from atomic overlap integrals. Experimental values of are typically between 0.8 and 1.0.

Alternatively, you can specify the value of in the
HOLE or EDGE card; however,
the meaning of the parameters in the ``feff.inp`' file is more
clear if you use the S02 card.

* let FEFF calculate S02 S02 0.0