To further disclosed the effects of entropy, we proposed another descriptor which only takes the most probable structure into consideration and called it q -ACSFs max . As shown in Figure , we presented the relationship between the number of rotatable bonds and root-mean-square deviation (RMSD) of trajectories generated from molecular dynamics simulations, from which high correlation was observed. A molecule with the highest number of rotatable bonds among PhysProp was detailed. The conformations generated by MD were grouped into three clusters according to their structural similarity (Details could be found in supporting information, Section S7.1), each cluster is colored separately. From the distribution of the potential, we could see that three representative structures (the dotted lines and the five point star) could almost cover the whole range. A subsequent principle component analysis also disclosed that 3 clusters may be sufficient as the top 3 principle components account for 65.3 % of the whole systems. (Figure ) The distribution of the number of rotatable bonds and RMSD for four distinct datasets was also drawn, a sharp peak was observed in the datasets PhysProp, Martel and Huuskonen. (Figure (a)-(c)) A somehow wide distribution was observed in datasets Star & Non-Star, which may account for the performance that the q -ACSFs con f outperform the q -ACSFs max over datasets Star & Non-Star where little differences were observed in other two datasets (Table ).