geometry rectangular

volume
     1.000000E+00    zone_0
     1.000000E+00    zone_1
     1.000000E+00    zone_2
     1.000000E+00    zone_3
end

mat_loading
    zone_0    mix_0
    zone_1    mix_1
    zone_2    mix_2
    zone_3    mix_3
end

mixture mix_0
    material mat_0 1 1
end

mixture mix_1
    material mat_1 1 1
end

mixture mix_2
    material mat_2 1 1
end

mixture mix_3
    material mat_3 1 1
end

