Examination of the solid state infrared spectra of the tetramethylammoniumcation in salts shows correlation of infrared spectral properties with C–H···X hydrogen bonding and crystal habits in these tetramethylammonium salts. The IR predicted crystal habits are comprised by experimental and theoretical data. A good relation between three data has been found. The C–H stretching region characteristic hydrogen bonding shifts in the above salts. In this research three complexes of tetramethylammoniumcation have been synthesized and the structures of them have been analyzed by correlation of vibrational data with crystal structures. These correlation shows that crystal symmetry (Tetrahedral), cation distortion (undistorted), site symmetry (D2d), unite cell symmetry (D4h7) for (CH3)4NPF6 and crystal symmetry (Tetrahedral), cation distortion (distorted), site symmetry (D2d), unite cell symmetry (D4h7) for (CH3)4NOH and crystal symmetry
(Tetrahedral), cation distortion (undistorted), site symmetry (D2d), unite cell symmetry (D4h7) for (CH3)4NF.