Especially, the DFT approach only needs a second order direct correlation function (DCF) of the coexistence bulk fluid as input, and is therefore applicable to the subcritical temperature region.

• 特别是密度泛函近似仅仅需要共存体相流体的二阶直接相关函数作为输入，因而可以应用于超临界与亚临界温度。