Abstract The structure of KLiSO4 at room temp erature was determined (C66) in 1925 by Bradley. The position of Li atom at the void on a triad was inferred but not measured. This result is in contradiction with the general theory of chemical bonding, so, recently, Meng and Cao presented a view disagreeing with it.We have redetermined the structure of KLiSO4, in particular the position of Li atom. New result shows that Li atom is located at x=1/3, y=2/3, z=0.1797(16) instead of x=1/3, y=2/3, z=0.3488 as described by Bradley. The former is roughly the same as that predicted by steric considerations in ref. . Four nearest O atoms around Li atom form a tetrahedroid.