The frustrated magnet clinoatacamite, γ-Cu₂(OH)₃Cl, is attracting a lot of interest after suggestions that at low temperature it forms an exotic quantum state termed a Valence Bond Solid (VBS) made from dimerised Cu²⁺ (S = ½) spins.[12] Key to the arguments surrounding this proposal were suggestions that the kagomé planes in the magnetic pyrochlore lattice of clinoatacamite are only weakly coupled, causing the system to behave as a quasi-2-dimensional magnet. This was reasoned from the near 95° angles made at the bridging oxygens that mediate exchange between the Cu ions that link the kagomé planes.

Recent work pointed out that this exchange model is inappropriate for γ-Cu₂(OH)₃Cl, where the oxygen is present as a μ₃-OH.[11] Further, it used symmetry calculations and neutron powder diffraction to show that the low temperature magnetic structure (T < 6 K) was canted and involved significant spin ordering on all the Cu²⁺ spins, which is incompatible with the interpretation of simultaneous VBS and Néel ordering. Correspondingly, clinoatacamite is best considered a distorted pyrochlore magnet. In this report we show detailed inelastic neutron scattering spectra and revisit the responses of this frustrated quantum magnet.