As a result, it is difficult to find H atoms in x-ray experiments. This can be accounted for to some extent by artificially up-weighting the higher angle reflections. The least-squares fitted x,y,z then more closely approximate the true nuclear positions, and difference maps are correspondingly less biased, and H atoms are more visible. Electron density map showing the hydrogen atoms of a Phenylalanine residue. Electron density map showing Hydrogen bond network.
Cyan contours represent hydrogen atoms.