1. The problem statement, all variables and given/known data Compute the form factor of rho(r) = rho0 * exp[-ln2*r^2/R^2] where rho0 and R are constants. 2. Relevant equations F(q) = 4pi/q [tex]\int[/tex]sin(q*r)rho(r)rdr where the limits of integration run from 0 to [tex]\infty[/tex] 3. The attempt at a solution This is probably more of a math problem, and I've tried everything mathematical I could think of to evaluate this integral: Substitution, Integration by parts, taylor approximation to turn the exponential into a polynomial in r, writing sin(q*r) in exponentials... But all of this got me nowhere fast. Then I tried looking up the integral in a table, but couldn't come across it in 30 pages worth of standard integrals. (Schaum series book) As a last resort, I tried numerical integration in excel using set values for R and q, but of course the answer depends very much on the values of R and q, so this offered me no insight. Thanks in advance for any help. Wynand.