# FPRIME

FPRIME emin emax estep

To calculate x-ray scattering factor $f^\prime$ far from the edge (only atomic part). The energy grid is regular in energy with estep between emin and emax. This is typically needed to find contributions from edges other than those calculated with the DANES card. Total scattering amplitude is:

$f^\prime(Q,E) = f_0(Q) + f^\prime(E) + i f^{\prime\prime}(E)$

In the dipole approximation $f^\prime$ and $f^{\prime\prime}$ do not depend on Q, but this is not true with quadrupole transitions added. This is currently neglected and

$f^\prime(E)$ = DANES(edge) + FPRIME(all other edges) + (total energy term in fpf0.dat)

$f^\prime(Q)$ is also tabulated in ‘fpf0.dat’; $f^{\prime\prime}$ is printed out by FPRIME in electronic units, and can be used to obtain total $f^\prime$. The total energy correction to $f^\prime$ is given in the first line of ‘fpf0.dat’ in Cromer-Liberman, and the more accurate Kissel-Pratt form. See our paper on elastic scattering amplitude for references and details.