Differences (GALAH, RAVE, APOGEE, (V–K), IRFM – our method) in T_eff as a function of the T_eff derived using our method on the x-axis. The dashed black lines indicate the difference values of −100 K, 0 K, and +100 K. Differently colored symbols represent the values from different sources: Inverted blue triangles show APOGEE spectroscopic estimates, black squares show GALAH IRFM estimates, green stars show RAVE IRFM estimates, red diamonds show our IRFM T_eff estimates, and pink hexagons show T_eff estimated using the T_eff vs. (V–K) relation from Bessell et al. (1998) with extinctions in V and K based on the E(B − V) values from APOGEE.