We request three days of beamtime on HRPD to study the crystallographic structures of six compounds containing a (distorted) frustrated antiferromagnetic lattice of Mo5+, 4d1 cations. Some of these compounds adopt a highly unusual spin−singlet valence bond state that is eliminated by structural distortion. Neutron diffraction will map the structural distortion as a function of composition and temperature and the data derived from these experiments will show which structural features are associated with the valence bond state. Distortions in perovskites can be subtle and so the high resolution of HRPD and counting times of 4 hrs are necessary. These compounds are also the subject of a proposal on EMU to use muons to examine the collapse of the valence bond state as a function of temperature and composition.