This proposal is a partial resubmission of the 5-51-460 one, which is currently being carried out. While part of the proposal is running smoothly, experiments in D10 found technical difficulties. These experiments are an important part of the proposal value.We are interested in the 3D long-range magnetic structure of the PNNBO triradical below TN=0.28 K, which remains unknown and for that reason is of our interest to determine it by using single crystal neutron diffraction at very low temperature.