Thanks a lot :)

U need IOP just for partial DOS calculations. However, local electronic DOSs can be easily extracted from output file of Gaussian.

thanks a lot :) what's the suitable IOP for PDOS?

add " pop=full IOp(3/33=1,3/36=-1) formcheck " to your input

you can use AOmix, Gaussum and Multiwfn to draw partial-DOS

for the gausssum creat the group.txt and by Multiwfn just follow easily the proposed options ( use *fchk file for Multiwfn input)