RRF is my Root Rational Fraction program, which does exact arithmetic on quantities that are square roots of rational fractions. It is intended mainly for manipulating the formulae of angular momentum theory, especially the Wigner 3j, 6j and 9j symbols. It can be used as a sort of desk calculator, or it can be used as a subroutine library in Fortran programs. Further details are available.
You can also use the program directly via the Web to calculate individual 3j, 6j or 9j symbols.
This page is maintained by Anthony Stone, and was last updated on 20 March, 2014.