Thanks Mr. Axel Kohlmeyer.
It worked.
pair_style hybrid eam/alloy sw lj/cut 4
pair_coeff * * eam/alloy Al99.eam.alloy Al NULL
pair_coeff * * Si.sw NULL Si
pair_coeff 1 2 lj/cut 0.4121 2.3216
I defined all 3 pairstyles but it caused this error.
“Pair coeff for hybrid has invalid style”
Thank You.