A new theoretical model of the triatomic molecular wake effect is proposed and applied to molecular ions D^＋3 and HD^＋2 while passing through a solid. The wake effects resulting from the reactions of the two similar ions with thin carbon foil are also investigated by using the Coulomb explosion technique. The experimental results are in good agreement with theoretical estimates and the molecular structure of HD^＋2 is determined by using the model.
