For running an Abinit job in parallel, you need to add the command mpirun in front of the abinit command and specify the number of cores (here we use 4) through the -n option of bsub:
sbatch --ntasks=4 [Slurm options] --wrap="mpirun abinit < test.files > output.log"
Here you need to replace [Slurm options] with Slurm parameters for the resource requirements of the job. Please find a documentation about the parameters of sbatch on the wiki page about the batch system. You do not need to set the -np for mpirun, as this will automatically be set by the batch system to the value that has been specified for the -n option of bsub.