e second derivative forms (normalised to unity when E=1,
if reasonable):

<P>
0 : Woods-Saxon  = P1 * 8 * E*(E-1) / (1+E)<SPAN CLASS="MATH"><IMG
 STYLE=""
 SRC="img87.svg"
 ALT="$^3$"></SPAN>
<BR>
1 : WS squared   = P1 * 4 * E*E / (1+E)<SPAN CLASS="MATH"><IMG
 STYLE=""
 SRC="img87.svg"
 ALT="$^3$"></SPAN>
<BR>
2 : Gaussian     = P1 * 2 * exp(-RH*RH) * RH
<BR>
3 : Yukawa       = P1 * E * (1/P3<SPAN CLASS="MATH"><IMG
 STYLE=""
 SRC="img37.svg"
 ALT="$^2$"></SPAN>. + 2/r<SPAN CLASS="MATH"><IMG
 STYLE=""
 SRC="