Comment on Percolation thresholds in the three-dimensional stick system

Comment on ”Percolation Thresholds in the Three-Dimensional Stick System”Z. N´eda and R. FlorianBabe¸s-Bolyai University, Dept. of Physicsstr. Kog˘alniceanu 1, RO-3400 Cluj, Romania(April 30, 1998)We discuss a classical mistake made in earlier publications on the stick percolation problem in3Dforgeneratingtherightisotropicconfigurationofsticks.Weexplaintheobservedsystematicdeviationsfromtheexcludedvolumerule.NewMCsimulationsconsideredbyusconfirmnicelytheapplicability of the volume theory.PACS numbers: 64.60.Ak, 02.50.Ng, 05.40.+jThe three-dimensional continuum percolation problem case, getting= π/4. Calculatingof permeable sticks with the form of capped cylinders for their ”isotropic” configurations the result would bewas considered by Monte Carlo simulations in Ref. [1]. =2/π. It is even more striking that in aThe authors report the dependence of the percolation following letter [4], confirming also the excluded volumethreshold on aspect ratio and on macroscopic anisotropy, theory, the authors do observe the systematic deviationdiscussing the results from the viewpoint of the excluded of the Monte Carlo results [1] for the isotropic case re-volume theory [2]. spective to the excluded volume rule (Fig. 2 in Ref. [4]),Throughout the paper [1] the authors claim to obtain but they fail in explaining it. In Ref. [4] the authorsthe isotropic distribution of the rods orientations by gen- argue that the systematic deviation is due to the ...