The comparison of CG and AA results indicates that, for the No.2-10 alkane molecules, the EX1 method significantly underestimates their interaction strength, with a calculated MAD value of 111.6 kg/m³. Specifically, for the BUT molecule, the computed density value of 14.6 kg/m³ is severely underestimated, suggesting that it has undergone vaporization under the given conditions, failing to accurately reproduce liquid properties. The severe deviation observed for BUT stems from the fact that the EX1 method treats each particle in the AA groups as mutually independent, leading to larger repulsive volumes and weaker interactions. For the No.10-14 cyclic and aromatic molecules, densities calculated using the EX1 method are close to those obtained from AA trajectories, with a calculated MAD value of 37.1 kg/m³. Compared to the EX1 method, the EX2 method tends to overestimate the interaction strength for most simulated systems, thereby leading to higher densities. For the No.1-14 molecules, the calculated MAD of using the EX2 method relative to AA data was 164.4 kg/m³, which is notably greater than the results calculated by the EX1 method.