variable  data_file       index ${input_dir}/data.conp
variable  pair_style      index 'zero 8.0'
variable  bond_style      index zero
variable  angle_style     index zero
variable  dihedral_style  index zero
variable  improper_style  index zero

atom_style       full
units            real

pair_style       ${pair_style}
bond_style       ${bond_style}
angle_style      ${angle_style}
dihedral_style   ${dihedral_style}
improper_style   ${improper_style}

read_data        ${data_file}

pair_coeff * *
bond_coeff *
angle_coeff *

group bot type 1
group top type 2
group ele type 1 2