The definition of cutoff radius of density

[yingxingcheng]

denspart/src/denspart/mbis.py

Lines 57 to 61 in 7ee05fb

	def get_cutoff_radius(self, density_cutoff):
	if density_cutoff <= 0.0:
	return np.inf
	population, exponent = self.pars
	return (np.log(population) - np.log(density_cutoff)) / exponent

Is the prefactor $\frac{\alpha^3_{Ai}}{8 \pi}$ missed in the definition of the cutoff radius of radial density?

$$\rho_{Ai}^0(\vec{r}) = N_{Ai} f_{Ai}(\vec{r}) = \frac{N_{Ai} \alpha^3_{Ai}}{8\pi}e^{-\alpha_{Ai}|\vec{r}-\vec{R}_A|}$$

[PaulWAyers]

It's impossible to say because the function isn't documented.

The constant factor is not going to drastically affect the cutoff, but I agree that it would be sensible to include it.

[tovrstra]

I also agree it would be better to include it (and document the method). Something along the following lines would be more fitting:

$$R_\text{cut}=-\frac{1}{\alpha}\bigl(\ln(\rho_\text{cut}) + \ln 8\pi - \ln N - 3\ln \alpha\bigr)$$

[yingxingcheng]

I think a minus sign is missing. $R_\text{cut}' = -R_\text{cut}$

[tovrstra]

Thanks. I've fixed it by editing my comment.

[tovrstra]

P.S. Long overdue, but I fixed it in 0182d1a