cluster     1   number of spheres in cluster     4
    1  -6.96900   2.00400  18.36900   0.700    1                                
    2  -6.01500   1.29500  17.35000   0.700    2                                
    3  -4.79600   1.34700  17.05500   0.700    3                                
    4  -6.73000   0.51100  16.70800   0.700    4