c/* %W% latest revision %G% %U% */ subroutine FFPN( q2, fcp, fcn ) ************************************************************************ c *** see R.H. Landau's program LPOTT, 1981 c *** Proton charge ff (also proton magnetic and neutron magnetic c *** if the number of rhos = 1) c *** Neutron charge form factor c *** q in fm-1 ************************************************************************ implicit real*8 (a-h, m, o-z) character*60 SCCSID data SCCSID / $ '%Z%%M% %I% Latest Revision %G% at %U%' / data x, un, mn / 18.2d+0, -1.91315d+0, 4.7548d+0/ ************************************************************************ ************************************************************************ fcp = 1./( (1. + q2/x)**2 ) fcn = -(un * q2 * 0.25/mn/mn) * fcp RETURN end