STATCW and STATCN: Fortran programs for conducting statistical tests for centrosymmetry

Two Fortran programs are described for conducting various statistical tests for centrosymmetry. The first program, STATCW, is for crystals that satisfy the requirements of basic Wilson distributions while the second, STATCN, is for any crystal for which the probability density functions of the normalized structure-factor-magnitude variable y for hypothesis testing are available only in the form of a numerical table. As well as seven quantitative statistical tests, the moments of truncated distributions are also included in these programs as test criteria and a unique decision is arrived at using suitable decision rules. The two programs were tested in a number of cases and typical results obtained are reported.