To determine the nature of this magnetic ground state we carried out PND using instrument D1B at the ILL on a 5 g non-deuterated sample of CrCl 2 (pym). We measured the neutron diffraction pattern at two temperatures: T = 1.5 K below T N , and T = 30 K above. We isolated the magnetic scattering from instrumental background and nuclear scattering contributions by subtracting the high temperature dataset from the low temperature dataset (Fig. ), which allowed us to identify the magnetic Bragg peaks. We were able to index these reflections with a propagation vector k = 1 2 00 and using symmetry-mode analysis in the ISODISTORT software suite 39 we identified there were two possible irreducible representations (irreps), mY - 1 and mY - 2 in Miller and Love's notation. After calibration of the nuclear scale factor through Rietveld refinement of nuclear structure against the high temperature dataset, we carried out Rietveld refinement of the magnetic structure using each irrep against the temperature subtracted dataset. We found for both nuclear and magnetic refinement that a hkl-dependent peak broadening term was necessary to account for the variation in measured peak widths. This showed that only the mY - 1 irrep was consistent with experimental data (Fig. ). The mY - 1 irrep lowers the symmetry of the structure to P c 2 1 /c with the magnetic unit cell relating to the nuclear cell as follows: a mag. = c nuc. , b mag. = b nuc. and c mag. = 2a nuc. (Fig. &).