n,$R^2$,descriptors 

2 ,  0.8297 , Target_mass| Ion_mass 

3 , 0.9871 , Target_heat_of_formation| Target_density| Ion_mass 
3 ,  0.9852 , Target_evaporatIon_heat| Target_density| Ion_mass 

4 ,  0.9966 , Target_heat_of_formation| Target_density| Target_covalent_radius_slater| Ion_mass 
4 ,  0.9956 , Target_melting_point| Target_boiling_point| Target_density| Ion_mass