# mac

TABI-PB parameter, multipole acceptance criterion (MAC), that controls distance ratio at which the method uses direct summation or Taylor approximation (a particle-cluster interaction) to calculate the integral kernels. The syntax is:

    mac {theta}

where `theta` is a floating-point number from 0 to 1 controlling the distance ratio. This multipole acceptance criterion (MAC) is \(\frac{r_c}{R}\leqslant \theta\), where \(r_c\) is the cluster radius, and \(R\) is the distance of the particle to the cluster center. If the above relationship is satisfied, the Taylor approximation will be used instead of direct summation. A typical value for this parameter is 0.8.