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# Ballone-Pastore-Galli-Gazzillo

$B(r)=\left[ 1+s\gamma \left( r\right) \right] ^{1/s}-1-\gamma \left(r\right)$
where $s=15/8$. It has its origins in the Martynov-Sarkisov closure ($s=2$). The value of $s$ can be determined by a self-consistency condition. Notice that for $s=1$ the BPGG approximation reduces to the hyper-netted chain closure.