  Incident angle dependence of reactions between graphene and hydrogen atoms
are obtained qualitatively by classical molecular dynamics simulation under the
NVE condition with modified Brenner reactive empirical bond order (REBO)
potential. Chemical reaction depends on two parameters, i.e., polar angle
$\theta$ and azimuthal angle $\phi$ of the incident hydrogen. From the
simulation results, it is found that the reaction rates strongly depend on
polar angle $\theta$. Reflection rate becomes larger with increasing $\theta$,
and the $\theta$ dependence of adsorption rate is also found. The $\theta$
dependence is caused by three dimensional structure of the small potential
barrier which covers adsorption sites. $\phi$ dependence of penetration rate is
also found for large $\theta$.
