SUNT[a] is the SU(N) generator in the fundamental representation.
See also: CA, CF, SUND, SUNDelta, SUNF, SUNSimplify.
Since is a noncommutative object, products have to separated by a dot (.).
The normalizaton of the generators is chosen in the standard way, therefore
In case you want , you need to include a factor 2Tf inside the trace.
|The FeynCalc Book||SUNSimplify||SUNTrace|