  The low-lying states of the $^{9}$Li nucleus are investigated with a unified
framework of microscopic structure and reaction models. In the structure model,
the wave function is fully antisymmetrized and the $^{9}$Li nucleus is
described as an $\alpha$ + $t$ + $n$ + $n$ four-body system, and low-lying
1/2$^{-}$, 3/2$^{-}$, 5/2$^{-}$, and 7/2$^{-}$ states are obtained by the
stochastic multi-configuration mixing method. Using these wave functions, the
quasi-elastic cross section at $E/A$ = 60 MeV and the elastic and inelastic
cross sections at $E/A$ = 50 MeV on the $^{12}$C target are calculated in the
framework of the microscopic coupled channel (MCC) method. The characteristic
inelastic angular distribution is seen in the 3/2$_{2}^{-}$ state, whose
$\alpha+t$ cluster structure and valence neutron configurations are discussed
in detail. We find the possibility of triaxial deformation and mixing of
di-neutron components in the $^{9}$Li nucleus.
