Secondly, we obtain the dielectric constant including the Debye relaxations and the high-frequency excesses with careful fitting . The polarization autocorre-lation is fitted to reduce the effect of the thermal noises instead of the dielectric constant itself. Two successive fitting methodologies are employed, which include the continuous relaxation time distribution method and discrete model regression. Employing these consecutive methodologies enables us to obtain a precise dielectric constant through molecular dynamics simulations, encompassing both dielectric relaxations and resonances.