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# Ballone-Pastore-Galli-Gazzillo

The **Ballone-Pastore-Galli-Gazillo** (BPGG) (1986) (Eq. 3.8 Ref. 1) closure relation,
developed for mixtures of hard spheres, is given by

where . It has its origins in the Martynov-Sarkisov closure (). The value of can be determined by a self-consistency condition. Notice that for the BPGG approximation reduces to the hyper-netted chain closure.