def METHOD_NAME(dgradflag):
    # simulation settings
    lmp.command("clear")
    lmp.command("units metal")
    lmp.command("boundary	p p p")
    lmp.command("atom_modify	map hash")
    lmp.command(f"lattice         bcc {latparam}")
    lmp.command(f"region		box block 0 {nx} 0 {ny} 0 {nz}")
    lmp.command(f"create_box	{ntypes} box")
    lmp.command(f"create_atoms	{ntypes} box")
    lmp.command("mass 		* 180.88")
    lmp.command("displace_atoms 	all random 0.01 0.01 0.01 123456")
    # potential settings
    snap_options = f'{rcutfac} {rfac0} {twojmax} {radelem1} {radelem2} {wj1} {wj2} rmin0 {rmin0} quadraticflag {quadratic} bzeroflag {bzero} switchflag {switch} bikflag {bikflag} dgradflag {dgradflag}'
    lmp.command(f"pair_style 	zero {rcutfac}")
    lmp.command(f"pair_coeff 	* *")
    lmp.command(f"pair_style 	zbl {zblcutinner} {zblcutouter}")
    lmp.command(f"pair_coeff 	* * {zblz} {zblz}")
    # define compute snap
    lmp.command(f"compute 	snap all snap {snap_options}")
    # run
    lmp.command(f"thermo 		100")
    lmp.command(f"run {nsteps}")