Prediction for the singlet-triplet excitation energy for the spinel MgTi${}_2$O${}_4$ using first-principles diffusion Monte Carlo

Brian Busemeyer, Gregory J. MacDougall, Lucas K. Wagner

The spinel, MgTi${}_2$O${}_4$, undergoes a transition into a dimerized state at low temperatures that is expected to be a spin singlet. However, no signature of a singlet-triplet trans…