A team in Russia suggested previously that quantum tunnelling might explain the terahertz-frequency spectra of water in beryl’s nanochannels. Kolesnikov says that he and his colleagues decided to study the system using neutrons because his co-author Larry Anovitz had large single crystals of beryl to hand. Their earlier study using neutron scattering and dielectric spectroscopy hinted that the reorientation of the water molecules might be hindered by some energy barrier, but the two techniques gave conflicting results.