  Utilizing a simplified quantum model approach, the low-energy inelastic
collision processes between yttrium atoms (ions) and hydrogen atoms have been
studied. Rate coefficients corresponding to the mutual neutralization, ion-pair
formation, excitation, and de-excitation processes for the above collision
systems have been provided in the temperature range of 1000-10000K. 3 ionic
states and 73 covalent states are considered in calculations for the collisions
of yttrium atoms with hydrogen atoms, which include 6 molecular symmetries and
4074 partial inelastic reaction processes. For the collisions of yttrium ions
with hydrogen atoms, 1 ionic state and 116 covalent states are included, which
related to 3 molecular symmetries and 13572 partial inelastic collision
processes. It is found that the rate coefficients for the mutual neutralization
process have a maximum at T = 6000K, which is an order of magnitude higher than
those of other processes. Notably, the positions of optimal windows for the
collisions of yttrium atoms and ions with hydrogen atoms are found near
electronic binding energy -2eV (Y) and -4.4eV (Y$^+$), respectively. The
scattering channels located in or near these optimal windows have
intermediate-to-large rate coefficients (greater than $10^{-12}$
cm$^3$s$^{-1}$). The reported data should be useful in the study of non-local
thermodynamic equilibrium modeling.
