The structure of molten LiF-BeF 2 solutions was studied by Xray diffraction fifty years ago by Vaslow and Narten using a MoK α lab X-ray source. They verified tetrahedral geometry for BeF complex ions as in the model developed by Baes , and output first nearest-neighbor (FNN) distances and coordination numbers (CN) for Be-F, Li-F, and F-F. They postulated corner sharing tetrahedra, showing a consistent Be-F CN of 4 for binary melts across the entire composition space from 100% LiF to 100% BeF 2 . This postulation was further supported by molecular dynamics models that predict FNN and CN for LiBeF 3 ; the Be-F values were within two standard deviations, F-F were identical between molecular dynamic (MD) predictions and experiments, and Li-F FNN distance predicted by MD at 760 °C was more than three standard deviations smaller than X-ray-measured values at 400 °C. Evidence of tetrahedral BeF in molten LiF-BeF 2 solutions is ubiquitous, beginning with measurements using X-ray diffraction and vibrational spectroscopy (infrared and Raman) along with molecular dynamics studies. Evidence of dimers and higher order oligomers increasing with the BeF 2 concentration has followed from Raman spectroscopy and thermodynamic models fit to measured activity coefficients and other thermo-chemical data. The formation of corner-sharing tetrahedral BeF 2 - 4 clusters (which was proposed from considering fluoroberyllate melts as analagous to SiO 4 melts) has been reinforced by modern molecular dynamics simulations. However, the ability to validate the intermediate-range melt structure predicted in molecular simulations is limited by the resolution of experimental X-ray diffraction data available in the literature. With the FNN structure of fluoro-beryllate melts described and validated, it now becomes possible to investigate the role of intermediate-range order on solvation mechanisms and other macroscopic physical and chemical properties of fluids. Thus, validating molecular dynamics models for their structure predictions beyond FNN would be highly impactful.