Another application for SMMs is in magnetocaloric refrigerants. A machine learning approach using experimental data has been able to predict novel SMMs that would have large entropy changes, and therefore more suitable for magnetic refrigeration. Three hypothetical SMMs are proposed for experimental synthesis: Cr 2 Gd 2 ( OAc ) 5 + , Mn 2 Gd 2 ( OAc ) 5 + , [ Fe 4 Gd 6 ( O 3 PCH 2 Ph ) 6 ( O 2 CtBu ) 14 ( MeCN ) 2 ] . The main SMM characteristics that contribute to the entropy properties include dimensionality and the coordinating ligands.