The QUBE force field achieves a root mean square (RMS) error of 0.42 Hz, which can be compared to 0.35 Hz for OPLS-AA/M. 1 Encouragingly, the error in the J couplings simulated using the QUBE force field is much lower than that of OPLS-AA (0.97 Hz) and OPLS-AA/L (0.79 Hz). With the arginine dipeptide excluded from the QUBE data, the error drops further to 0.33 Hz. Residue-specific arginine backbone torsional parameters could be computed, however given that the φ/ψ distribution of arginine occupies the main conformations expected, this is not investigated in this work.