Absorption correction A* for cylindrical and spherical samples with extended range and high accuracy calculated by the Thorkildsen and Larsen analytical method.

Tables of the absorption correction A* for cylindrical and spherical crystals were calculated by the Thorkildsen & Larsen [Acta Cryst. (1998), A54, 186-190] analytical method in the range of 0 ≤ μR ≤ 30 and 0 ≤ θ ≤ 90° with accuracies of 10(-6) for cylindrical crystals and 2.0 × 10(-6) for spherical crystals. Bivariate Chebyshev polynomial fitting formulae for A* are also provided for both cases. The maximum fitting error for spherical crystals is 6 × 10(-3) and the average error ranges from 7 × 10(-5) to 3 × 10(-4). All the important tables and the fitting program are provided in the supplementary material.