No significant difference is observed for the HS3 fragment when comparing the two approaches, as shown in Figure (a) and (b). This is consistent with the results obtained from the power spectrum calculation, which also showed no significant change for the HS3 fragment. In contrast, the HS30 fragment exhibits a deviation in the match of the coarse-grained distri-bution to the reference for the restricted model, as observed in Figure ). This behavior is also evident in other angular distributions of this fragment (see Figure ). Due to the restriction of the angle force constants, the model does not fully reproduce the reference distribution. However, the deviation remains moderate, and the mean value is accurately captured.