Are you looking for sphere specific values?

You can get all values using the python API for liggghts.

form liggghts import liggghts() # Load the library

lmp = liggghts() # Start LIGGGHTS

lmp.file("in.liggghts") # Read an input file

forces = lmp.extract_atom("f",2) # extract forces

You would first have to build liggghts as a library.

I use UMAT for my project in soils plasticity.