二元高斯核模型的相不稳定性研究

Investigation of phase instability in the binary Gaussian core model

从考虑巨势Ω在平衡点附近随密度的微小涨落δρα(r)的变化出发,由系统的关联函数可以研究描述高分子链二元系统的相不稳定性.在超网链(HNC)近似下研究了二元高斯核模型的相不稳定性,得到了它的相不稳定线,同时确定此相变是由浓度涨落为主的相不稳定性引起的退混合相变.将HNC近似下的结果与随机相近似下的结果进行了比较.

By considering the fluctuation of grand potential Ωaround equilibrium with respect to small density fluctuations δρα （ r）, the phase instability of binary Gaussian core model has been investigated and characterized. The spinodal of this model is obtained by using its direct correlation functions calculated in the hypernetted chain（HNC） approximation. Our analysis shows that this phase transition is predominately demixing. The results in HNC approximation have been compared with that in the random phase approximation.