　Usually the size of most water clusters "experiment" is mostly implemented by "NMR test", the test value refers to the NMR FWHM (Full-Width Half-Maximum, FWHM), good water (water or the Japanese longevity village water) small molecules, the FWHM is relatively small (about 50Hz), tap water molecules is large, the FWHM is relatively large (about 120Hz). In fact, in the scientific literature and there is no credible evidence to prove that the width and the molecular size of the study of ITRI 's mission is that saving water and tap water of the PI NMR FWHM is almost the same. So if the half height of the measured water sample is small, the water molecules have become smaller.