formula

$\beta=1.75 \alpha_{[x],max} \alpha_{[y],max} \alpha_{[z],max} -1.11 (\alpha_{[x],max} \alpha_{[y],max}+\alpha_{[y],max}\alpha_{[z],max}+\alpha_{[z],max}\alpha_{[x],max}) \\ + 0.544 (\alpha_{[x],max}+\alpha_{[y],max}+\alpha_{[z]}) - 0.132$