  The growth of thin amorphous hydrogenated carbon films (a-C:H) on diamond
(111) surface from the bombardment of CH2 radicals is studied using molecular
dynamics simulations. The structural analysis shows that the local structure
(e.g., the first coordination number of C atoms) of a-C:H depends critically on
the content of hydrogen. The increase of kinetic energy of incident radicals
leads to the decrease of hydrogen content, which subsequently changes the ratio
of sp3 bonded C atoms in a-C:H.
