A compound comprising a ligand LA according to formula (I) as well as, a first device and a formulation including the same are disclosed. In the structure of formula (I): ring A is a 5- or 6-membered heteroaryl ring; X1 is C or N; RA is mono-, bi-, tri-, tetradentate, or unsubstituted; RA, R10, R11, R12, R13, R14, R15, R16, and R17 are independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof, any adjacent substituents of RA, R10, R11, R12, R13, R14, R15, R16, and R17 are optionally joined to form a fused ring; the dashed lines represent bonds to a metal M; and metal M has an atomic number greater than 40.