Percolation threshold


The percolation threshold is a mathematical concept in percolation theory that describes the formation of long-range connectivity in random systems. Below the threshold a giant connected component does not exist; while above it, there exists a giant component of the order of system size. In engineering and coffee making, percolation represents the flow of fluids through porous media, but in the mathematics and physics worlds it generally refers to simplified lattice models of random systems or networks, and the nature of the connectivity in them. The percolation threshold is the critical value of the occupation probability p, or more generally a critical surface for a group of parameters p1, p2,..., such that infinite connectivity first occurs.

Percolation models

The most common percolation model is to take a regular lattice, like a square lattice, and make it into a random network by randomly "occupying" sites or bonds with a statistically independent probability p. At a critical threshold pc, large clusters and long-range connectivity first appears, and this is called the percolation threshold. Depending on the method for obtaining the random network, one distinguishes between the site percolation threshold and the bond percolation threshold. More general systems have several probabilities p1, p2, etc., and the transition is characterized by a critical surface or manifold. One can also consider continuum systems, such as overlapping disks and spheres placed randomly, or the negative space.
In the systems described so far, it has been assumed that the occupation of a site or bond is completely random—this is the so-called Bernoulli percolation. For a continuum system, random occupancy corresponds to the points being placed by a Poisson process. Further variations involve correlated percolation, such as percolation clusters related to Ising and Potts models of ferromagnets, in which the bonds are put down by the Fortuin-Kasteleyn method. In bootstrap or k-sat percolation, sites and/or bonds are first occupied and then successively culled from a system if a site does not have at least k neighbors. Another important model of percolation, in a different universality class altogether, is directed percolation, where connectivity along a bond depends upon the direction of the flow.
Over the last several decades, a tremendous amount of work has gone into finding exact and approximate values of the percolation thresholds for a variety of these systems. Exact thresholds are only known for certain two-dimensional lattices that can be broken up into a self-dual array, such that under a triangle-triangle transformation, the system remains the same. Studies using numerical methods have led to numerous improvements in algorithms and several theoretical discoveries.
Simply duality in two dimensions implies that all fully triangulated lattices all have site thresholds of 1/2, and self-dual lattices have bond thresholds of 1/2.
The notation such as comes from Grünbaum and Shephard, and indicates that around a given vertex, going in the clockwise direction, one encounters first a square and then two octagons. Besides the eleven Archimedean lattices composed of regular polygons with every site equivalent, many other more complicated lattices with sites of different classes have been studied.
Error bars in the last digit or digits are shown by numbers in parentheses. Thus, 0.729724 signifies 0.729724 ± 0.000003, and 0.74042195 signifies 0.74042195 ± 0.00000080. The error bars variously represent one or two standard deviations in net error, or an empirical confidence interval.

Percolation on 2D lattices

Thresholds on Archimedean lattices

This is a picture of the 11 Archimedean Lattices or uniform tilings, in which all polygons are regular and each vertex is surrounded by the same sequence of polygons. The notation for example means that every vertex is surrounded by four triangles and one hexagon. Drawings from. See also Uniform tilings.
LatticezSite percolation thresholdBond percolation threshold
3-12 or 330.807900764... = 1/20.74042195, 0.74042077 0.740420800, 0.7404207988509, 0.740420798850811610,
cross, truncated trihexagonal 330.7478008, 0.7478060.6937314, 0.69373383, 0.693733124922
square octagon, bathroom tile, 4-8, truncated square
3-0.7297232, 0.7297240.6768, 0.67680232,
0.6768031269, 0.6768031243900113,
honeycomb 330.6962, 0.697040230, 0.6970402, 0.6970413, 0.697043,0.652703645... = 1-2 sin, 1+ p3-3p2=0
kagome 440.652703645... = 1 − 2 sin0.5244053, 0.52440516, 0.52440499, 0.524404978, 0.52440572..., 0.52440500,
0.524404999173, 0.524404999167439 0.52440499916744820
ruby, rhombitrihexagonal 440.62181207, 0.6218190.52483258, 0.5248311, 0.524831461573
square 440.59274, 0.59274605079210, 0.59274601, 0.59274605095, 0.59274621, 0.59274621, 0.59274598, 0.59274605, 0.593,
0.591,
0.569
1/2
snub hexagonal, maple leaf 550.5794980.43430621, 0.43432764, 0.4343283172240,
snub square, puzzle 550.5508060.41413743, 0.4141378476, 0.4141378565917,
frieze, elongated triangular550.550213, 0.55020.4196, 0.41964191, 0.41964044, 0.41964035886369
triangular 661/20.347296355... = 2 sin, 1 + p3 − 3p = 0

Note: sometimes "hexagonal" is used in place of honeycomb, although in some fields, a triangular lattice is also called a hexagonal lattice. z = bulk coordination number.

2d lattices with extended and complex neighborhoods

In this section, sq corresponds to square-NN+2NN+3NN, etc.
LatticezSite percolation thresholdBond percolation threshold
sq,,,: square-NN, 2NN, 3NN, 5NN40.592...
sq,,: NN+2NN, 2NN+3NN, 3NN+5NN80.407... 0.25036834, 0.2503685
sq: NN+3NN80.3370.2214995
sq: 2NN+5NN80.337
hc: honeycomb-NN+2NN+3NN120.300
tri: triangular-NN+2NN120.295,
tri: triangular-2NN+3NN120.232020,
sq: square-4NN80.270...
sq: square-NN+5NN80.277
sq: square-NN+2NN+3NN120.292, 0.290 0.288,0.1522203
sq: square-2NN+3NN+5NN120.288
sq: square-NN+4NN120.236
sq: square-2NN+4NN120.225
tri: triangular-4NN120.192450
tri: triangular-NN+2NN+3NN180.225, 0.215459
square: 3NN+4NN120.221
square: NN+2NN+5NN120.2400.13805374
square: NN+3NN+5NN120.233
square: 4NN+5NN120.199
square: NN+2NN+4NN160.219
square: NN+3NN+4NN160.208
square: 2NN+3NN+4NN160.202
square: NN+4NN+5NN160.187
square: 2NN+4NN+5NN160.182
square: 3NN+4NN+5NN160.179
square: NN+2NN+3NN+5NN160.2080.1032177
triangular: 4NN+5NN180.140250,
square: NN+2NN+3NN+4NN200.196 0.1967240.0841509
square: NN+2NN+4NN+5NN200.177
square: NN+3NN+4NN+5NN200.172
square: 2NN+3NN+4NN+5NN200.167
square: NN+2NN+3NN+5NN+6NN200.0783110
square: NN+2NN+3NN+4NN+5NN240.164
triangular: NN+4NN+5NN240.131660
square: NN+...+6NN280.0558493
triangular: 2NN+3NN+4NN+5NN300.117460
triangular: NN+2NN+3NN+4NN+5NN
360.115740
square: NN+...+7NN360.04169608
square: square distance ≤ 4400.105
square: NN+..+8NN440.095765
square: NN+..+9NN480.02974268
square: NN+...+11NN600.0230119
square: NN+...+32NN2240.0053050415 708 15 1.102 812
square: NN+...+86NN 7080.001557644
square: NN+...+141NN 12240.000880188
square: NN+...+185NN 16520.000645458
square: NN+...+317NN 30000.000349601
square: NN+...+413NN 40160.0002594722
square: square distance ≤ 6840.049
square: square distance ≤ 81440.028
square: square distance ≤ 102200.019
2x2 overlapping squares*0.58365
3x3 overlapping squares*0.59586

Here NN = nearest neighbor, 2NN = second nearest neighbor, 3NN = third nearest neighbor, etc. These are also called 2N, 3N, 4N respectively in some papers.

Site-bond percolation in 2D

Site bond percolation.
LatticezSite percolation thresholdBond percolation threshold
square440.6151850.95
0.6672800.85
0.7321000.75
0.750.726195
0.8155600.65
0.850.615810
0.950.533620

* For more values, see
Approximate formula for a honeycomb lattice
LatticezThresholdNotes
honeycomb33
when equal: ps = pb = 0.82199
approximate formula, ps = site prob., pb = bond prob., t = 1 − 2 sin

Archimedean duals (Laves lattices)

Laves lattices are the duals to the Archimedean lattices. Drawings from. See also Uniform tilings.
LatticezSite percolation thresholdBond percolation threshold
Cairo pentagonal
D=+
3,43⅓0.6501834, 0.6501840.585863... = 1 − pcbond
Pentagonal D=+3,43⅓0.6470471, 0.647084, 0.64710.580358... = 1 − pcbond, 0.5800
D=+3,63 3/50.6394470.565694... = 1 − pcbond
dice, rhombille tiling
D = +
3,640.5851, 0.5850400.475595... = 1 − pcbond
ruby dual
D = + +
3,4,640.5824100.475167... = 1 − pcbond
union jack, tetrakis square tiling
D = +
4,861/20.323197... = 1 − pcbond
bisected hexagon, cross dual
D= ++
4,6,1261/20.306266... = 1 − pcbond
asanoha
D=+
3,1261/20.259579... = 1 − pcbond

2-uniform lattices

Top 3 lattices: #13 #12 #36


Bottom 3 lattices: #34 #37 #11
Top 2 lattices: #35 #30


Bottom 2 lattices: #41 #42
Top 4 lattices: #22 #23 #21 #20


Bottom 3 lattices: #16 #17 #15
Top 2 lattices: #31 #32


Bottom lattice: #33
#LatticezSite percolation thresholdBond percolation threshold
41 + 4,33.50.76800.67493252
42 + 4,330.71570.64536587
36 + 6,44 0.68080.55778329
15 + 4,440.64990.53632487
34 + 6,44 0.63290.51707873
16 + 4,440.62860.51891529
17 + *4,440.62790.51769462
35 + 4,440.62210.51973831
11 + 5,44.50.61710.48921280
37 + 5,44.50.58850.47229486
30 + 5,44.50.58830.46573078
23 + 5,44.50.57200.45844622
22 + 5,44 0.56480.44528611
12 + 6,55 0.56070.41109890
33 + 5,550.55050.41628021
32 + 5,550.55040.41549285
31 + 6,55 0.54400.40379585
13 + 6,55.50.54070.38914898
21 + 6,55 0.53420.39491996
20 + 6,55.50.52580.38285085

Inhomogeneous 2-uniform lattice

This figure shows something similar to the 2-uniform lattice #37, except the polygons are not all regular—there is a rectangle in the place of the two squares—and the size of the polygons is changed. This lattice is in the isoradial representation in which each polygon is inscribed in a circle of unit radius.
The two squares in the 2-uniform lattice must now be represented as a single rectangle in order to satisfy the isoradial condition.
The lattice is shown by black edges, and the dual lattice by red dashed lines. The green circles show the isoradial constraint on both the original and dual lattices. The yellow polygons highlight the three types of polygons on the lattice, and the pink polygons highlight the two types of polygons on the dual lattice. The lattice has vertex types +, while
the dual lattice has vertex types +++. The critical point is where the longer
bonds have occupation probability p = 2 sin = 0.347296... which is the bond percolation threshold on a triangular lattice, and the shorter bonds have
occupation probability 1 − 2 sin = 0.652703..., which is the bond percolation on a hexagonal lattice. These results follow from the isoradial condition but also follow from applying the star-triangle transformation to certain stars on the honeycomb lattice. Finally, it can be generalized to having three different probabilities in the three different directions, p1, p2 and p3 for the long bonds, and,, and for the short bonds, where p1, p2 and p3 satisfy the critical surface for the inhomogeneous triangular lattice.

Thresholds on 2D bow-tie and martini lattices

To the left, center, and right are: the martini lattice, the martini-A lattice, the martini-B lattice. Below: the martini covering/medial lattice, same as the 2×2, 1×1 subnet for kagome-type lattices.
Some other examples of generalized bow-tie lattices and the duals of the lattices :
LatticezSite percolation thresholdBond percolation threshold
martini +330.764826..., 1 + p4 − 3p3 = 00.707107... = 1/
bow-tie 3,43 1/70.672929..., 1 − 2p3 − 2p4 − 2p5 − 7p6 + 18p7 + 11p8 − 35p9 + 21p10 − 4p11 = 0
bow-tie 3,43⅓0.625457..., 1 − 2p2 − 3p3 + 4p4p5 = 0
martini-A +3,43⅓1/0.625457..., 1 − 2p2 − 3p3 + 4p4p5 = 0
bow-tie dual 3,43⅔0.595482..., 1-pcbond
bow-tie 3,4,63⅔0.533213..., 1 − p − 2p3 -4p4-4p5+156+ 13p7-36p8+19p9+ p10 + p11=0
martini covering/medial + 440.707107... = 1/0.57086651
martini-B + 3, 540.618034... = 2/, 1- p2p = 01/2
bow-tie dual 3,4,84 2/50.466787..., 1 − pcbond
bow-tie + 4,650.5472, 0.54791480.404518..., 1 − p − 6p2 + 6p3p5 = 0
bow-tie dual 3,6,850.374543..., 1 − pcbond
bow-tie dual 3,6,100.547... = pcsite0.327071..., 1 − pcbond
martini dual + 3,961/20.292893... = 1 − 1/

Thresholds on 2D covering, medial, and matching lattices

LatticezSite percolation thresholdBond percolation threshold
covering/medial44pcbond = 0.693731...0.5593140, 0.559315
covering/medial, square kagome44pcbond = 0.676803...0.544798017, 0.54479793
medial440.5247495
medial440.51276
medial440.512682929
medial440.5125245984
square covering 661/20.3371
square matching lattice 881 − pcsite = 0.407253...0.25036834

covering/medial lattice
covering/medial lattice
covering/medial lattice, equivalent to the kagome subnet, and in black, the dual of these lattices.
covering/medial lattice, medial dual, shown in red, with medial lattice in light gray behind it. The pattern on the left appears in Iranian tilework.

Thresholds on 2D chimera non-planar lattices

Thresholds on subnet lattices

The 2 x 2, 3 x 3, and 4 x 4 subnet kagome lattices. The 2 × 2 subnet is also known as the "triangular kagome" lattice.
LatticezSite percolation thresholdBond percolation threshold
checkerboard – 2 × 2 subnet4,30.596303
checkerboard – 4 × 4 subnet4,30.633685
checkerboard – 8 × 8 subnet4,30.642318
checkerboard – 16 × 16 subnet4,30.64237
checkerboard – 32 × 32 subnet4,30.64219
checkerboard – subnet4,30.642216
kagome – 2 × 2 subnet = covering/medial4pcbond = 0.74042077...0.600861966960, 0.6008624, 0.60086193
kagome – 3 × 3 subnet40.6193296, 0.61933176, 0.61933044
kagome – 4 × 4 subnet40.625365, 0.62536424
kagome – subnet40.628961
kagome – : subnet = martini covering/medial4pcbond = 1/ = 0.707107...0.57086648
kagome – : subnet4,30.728355596425196...0.58609776
kagome – : subnet0.738348473943256...
kagome – : subnet0.743548682503071...
kagome – : subnet0.746418147634282...
kagome – : subnet0.61091770
triangular – 2 × 2 subnet6,40.471628788
triangular – 3 × 3 subnet6,40.509077793
triangular – 4 × 4 subnet6,40.524364822
triangular – 5 × 5 subnet6,40.5315976
triangular – subnet6,40.53993

Thresholds of random sequentially adsorbed objects

systemzSite threshold
dimers on a honeycomb lattice30.69, 0.6653
dimers on a triangular lattice60.4872, 0.4873, 0.5157
linear 4-mers on a triangular lattice60.5220
linear 8-mers on a triangular lattice60.5281
linear 12-mers on a triangular lattice60.5298
linear 16-mers on a triangular lattice60.5328
linear 32-mers on a triangular lattice60.5407
linear 64-mers on a triangular lattice60.5455
linear 80-mers on a triangular lattice60.5500
linear k on a triangular lattice60.582
dimers and 5% impurities, triangular lattice60.4832
parallel dimers on a square lattice40.5863
dimers on a square lattice40.5617, 0.5618, 0.562, 0.5713
linear 3-mers on a square lattice40.528
3-site 120° angle, 5% impurities, triangular lattice60.4574
3-site triangles, 5% impurities, triangular lattice60.5222
linear trimers and 5% impurities, triangular lattice60.4603
linear 4-mers on a square lattice40.504
linear 5-mers on a square lattice40.490
linear 6-mers on a square lattice40.479
linear 8-mers on a square lattice40.474, 0.4697
linear 10-mers on a square lattice40.469
linear 16-mers on a square lattice40.4639
linear 32-mers on a square lattice40.4747

The threshold gives the fraction of sites occupied by the objects when site percolation first takes place. For longer dimers see Ref.

Thresholds of full dimer coverings of two dimensional lattices

Here, we are dealing with networks that are obtained by covering a lattice with dimers, and then consider bond percolation on the remaining bonds. In discrete mathematics, this problem is known as the 'perfect matching' or the 'dimer covering' problem.
systemzBond threshold
Parallel covering, square lattice60.381966...
Shifted covering, square lattice60.347296...
Staggered covering, square lattice60.376825
Random covering, square lattice60.367713
Parallel covering, triangular lattice100.237418...
Staggered covering, triangular lattice100.237497
Random covering, triangular lattice100.235340

Thresholds of polymers (random walks) on a square lattice

System is composed of ordinary random walks of length l on the square lattice.
l zBond percolation
140.5
240.47697
440.44892
840.41880

Thresholds of self-avoiding walks of length k added by random sequential adsorption

kzSite thresholdsBond thresholds
140.5930.5009
240.5640.4859
340.5520.4732
440.5420.4630
540.5310.4565
640.5220.4497
740.5110.4423
840.5020.4348
940.4930.4291
1040.4880.4232
1140.4820.4159
1240.4760.4114
1340.4710.4061
1440.4670.4011
1540.40110.3979

Thresholds on 2D inhomogeneous lattices

Thresholds for 2D continuum models

SystemΦcηcnc
Disks of radius r0.67634831, 0.6763475, 0.676339, 0.6764, 0.6766, 0.676, 0.679, 0.674 0.676,1.12808737, 1.128085, 1.128059, 1.13, 0.81.43632545, 1.436322, 1.436289, 1.436320, 1.436323, 1.438, 1.216
Ellipses, ε = 1.50.00430.004312.059081
Ellipses, ε = 5/30.651.052.28
Ellipses, aspect ratio ε = 20.6287945, 0.630.991000, 0.992.523560, 2.5
Ellipses, ε = 30.560.823.157339, 3.14
Ellipses, ε = 40.50.693.569706, 3.5
Ellipses, ε = 50.455, 0.455, 0.460.6073.861262, 3.86
Ellipses, ε = 100.301, 0.303, 0.300.358 0.364.590416 4.56, 4.5
Ellipses, ε = 200.178, 0.170.1965.062313, 4.99
Ellipses, ε = 500.0810.0845.393863, 5.38
Ellipses, ε = 1000.04170.04265.513464, 5.42
Ellipses, ε = 2000.0210.02125.40
Ellipses, ε = 10000.00430.004315.624756, 5.5
Superellipses, ε = 1, m = 1.50.671
Superellipses, ε = 2.5, m = 1.50.599
Superellipses, ε = 5, m = 1.50.469
Superellipses, ε = 10, m = 1.50.322
disco-rectangles, ε = 1.51.894
disco-rectangles, ε = 22.245
Aligned squares of side0.66675, 0.66674349, 0.66653, 0.6666, 0.6681.09884280, 1.0982, 1.0981.09884280, 1.0982, 1.098
Randomly oriented squares0.62554075, 0.6254 0.625,0.9822723, 0.9819 0.9822780.9822723, 0.9819 0.982278
Rectangles, ε = 1.10.6248700.9804841.078532
Rectangles, ε = 20.5906350.8931471.786294
Rectangles, ε = 30.54059830.7778302.333491
Rectangles, ε = 40.49481450.6828302.731318
Rectangles, ε = 50.4551398, 0.4510.6072263.036130
Rectangles, ε = 100.3233507, 0.3190.39060223.906022
Rectangles, ε = 200.20485180.22922684.584535
Rectangles, ε = 500.097855130.10298025.149008
Rectangles, ε = 1000.05236760.05378865.378856
Rectangles, ε = 2000.027145260.027520505.504099
Rectangles, ε = 10000.005594240.005609955.609947
Sticks of length5.6372858, 5.63726, 5.63724
Power-law disks, x=2.050.9934.900.0380
Power-law disks, x=2.250.85911.9590.06930
Power-law disks, x = 2.50.78361.53070.09745
Power-law disks, x = 40.695431.188530.18916
Power-law disks, x = 50.686431.15970.22149
Power-law disks, x = 60.682411.14700.24340
Power-law disks, x=70.68031.1400.25933
Power-law disks, x=80.679171.13680.27140
Power-law disks, x = 90.678561.13490.28098
Voids around disks of radius r1 − Φc = 0.32355169, 0.318, 0.3261

equals critical total area for disks, where N is the number of objects and L is the system size.
gives the number of disk centers within the circle of influence.
is the critical disk radius.
for ellipses of semi-major and semi-minor axes of a and b, respectively. Aspect ratio with.
for rectangles of dimensions and. Aspect ratio with.
for power-law distributed disks with,.
equals critical area fraction.
equals number of objects of maximum length per unit area.
For ellipses,
For void percolation, is the critical void fraction.
For more ellipse values, see
For more rectangle values, see
Both ellipses and rectangles belong to the superellipses, with. For more percolation values of superellipses, see.
For the monodisperse particle systems, the percolation thresholds of concave-shaped superdisks are obtained as seen in
For binary dispersions of disks, see

Thresholds on 2D random and quasi-lattices

*Theoretical estimate

Thresholds on 2D correlated systems

Assuming power-law correlations
latticeαSite percolation thresholdBond percolation threshold
square30.561406
square20.550143
square0.10.508

Thresholds on slabs

h is the thickness of the slab, h × ∞ × ∞. Boundary conditions refer to the top and bottom planes of the slab.
LatticehzSite percolation thresholdBond percolation threshold
simple cubic 2550.47424, 0.4756
bcc 20.4155
hcp 20.2828
diamond 20.5451
simple cubic 30.4264
bcc 30.3531
bcc 30.21113018
hcp 30.2548
diamond 30.5044
simple cubic 40.3997, 0.3998
bcc 40.3232
bcc 40.20235168
hcp 40.2405
diamond 40.4842
simple cubic 5660.278102
simple cubic 60.3708
simple cubic 6660.272380
bcc 60.2948
hcp 60.2261
diamond 60.4642
simple cubic 7660.34595140.268459
simple cubic 80.3557, 0.3565
simple cubic 8660.265615
bcc 80.2811
hcp 80.2190
diamond 80.4549
simple cubic 120.3411
bcc 120.2688
hcp 120.2117
diamond 120.4456
simple cubic 160.3219, 0.3339
bcc 160.2622
hcp 160.2086
diamond 160.4415
simple cubic 320.3219,
simple cubic 640.3165,
simple cubic 1280.31398,

Thresholds on 3D lattices

Latticezfilling factor*filling fraction*Site percolation thresholdBond percolation threshold-
-a oxide 23 322.40.748713= 1/2 = 0.742334-
-b oxide 23 322.40.2330.1740.745317= 1/2 = 0.739388-
silicon dioxide 4,222 ⅔0.638683-
Modified -b32,22 ⅔0.627-
-a330.5779620.555700-
-a gyroid330.5714040.551060-
-b330.5654420.546694-
cubic oxide 6,233.50.524652-
bcc dual40.45600.4031-
ice Ih44π / 16 = 0.3400870.1470.4330.388-
diamond 44π / 16 = 0.3400870.14623320.4299, 0.4299870, 0.426, 0.4297
0.4301,
0.428,
0.425,
0.425,
0.436,
0.3895892, 0.3893, 0.3893,
0.388, 0.3886,
0.388
0.390,
-
diamond dual6 2/30.39040.2350-
3D kagome 6π / 12 = 0.370240.14420.3895 =pc for diamond dual and pc for diamond lattice0.2709-
Bow-tie stack dual5⅓0.34800.2853-
honeycomb stack550.37010.3093-
octagonal stack dual550.38400.3168-
pentagonal stack5⅓0.33940.2793-
kagome stack660.4534500.15170.33460.2563-
fcc dual42,85 1/30.33410.2703-
simple cubic66π / 6 = 0.52359880.16315740.307, 0.307, 0.3115, 0.3116077, 0.311604,
0.311605,
0.311600,
0.3116077,
0.3116081,
0.3116080, 0.3116060, 0.3116004,
0.31160768
0.247, 0.2479, 0.2488, 0.24881182, 0.2488125,
0.2488126,
-
hcp dual44,825 1/30.31010.2573-
dice stack5,86π / 9 = 0.6046000.18130.29980.2378-
bow-tie stack770.28220.2092-
Stacked triangular / simple hexagonal880.26240, 0.2625, 0.26230.18602, 0.1859-
octagonal stack6,1080.25240.1752-
bcc880.243, 0.243,
0.2459615, 0.2460, 0.2464, 0.2458
0.178, 0.1795, 0.18025,
0.1802875,
-
simple cubic with 3NN 880.2455, 0.2457-
fcc1212π / = 0.7404800.1475300.195, 0.198, 0.1998, 0.1992365, 0.19923517, 0.19940.1198 0.1201635-
hcp1212π / = 0.7404800.1475450.195,
0.1992555
0.1201640
0.119
-
La2−x Srx Cu O412120.19927-
simple cubic with 2NN 12120.1991-
simple cubic with NN+4NN12120.150400.1068263-
simple cubic with 3NN+4NN14140.204900.1012133-
bcc NN+2NN 14140.175, 0.16860.0991-
Nanotube fibers on FCC14140.1533-
simple cubic with NN+3NN14140.14200.0920213-
simple cubic with 2NN+4NN18180.159500.0751589-
simple cubic with NN+2NN18180.137, 0.136 0.1372, 0.137350.0752326-
fcc with NN+2NN 18180.136-
simple cubic with short-length correlation6+6+0.126-
simple cubic with NN+3NN+4NN20200.119200.0624379-
simple cubic with 2NN+3NN20200.10360.0629283-
simple cubic with NN+2NN+4NN24240.114400.0533056-
simple cubic with 2NN+3NN+4NN26260.113300.0474609-
simple cubic with NN+2NN+3NN26260.097, 0.0976, 0.09764450.0497080-
bcc with NN+2NN+3NN26260.095-
simple cubic with NN+2NN+3NN+4NN32320.100000.0392312-
fcc with NN+2NN+3NN42420.061, 0.0610
fcc with NN+2NN+3NN+4NN54540.0500

Filling factor = fraction of space filled by touching spheres at every lattice site. Also called Atomic Packing Factor.
Filling fraction = filling factor * pc.
NN = nearest neighbor, 2NN = next-nearest neighbor, 3NN = next-next-nearest neighbor, etc.
Question: the bond thresholds for the hcp and fcc lattice
agree within the small statistical error. Are they identical,
and if not, how far apart are they? Which threshold is expected to be bigger? Similarly for the ice and diamond lattices. See
Systempolymer Φc
percolating excluded volume of athermal polymer matrix 0.4304

Dimer percolation in 3D

SystemSite percolation thresholdBond percolation threshold
Simple cubic0.2555

Thresholds for 3D continuum models

All overlapping except for jammed spheres and polymer matrix.
SystemΦcηc
Spheres of radius r0.2895, 0.2896, 0.289573, 0.2896, 0.28540.3418, 0.341889, 0.3360,
0.34189,
Oblate ellipsoids with major radius r and aspect ratio 4/30.28310.3328
Prolate ellipsoids with minor radius r and aspect ratio 3/20.2757, 0.27950.3278
Oblate ellipsoids with major radius r and aspect ratio 20.2537, 0.26290.3050
Prolate ellipsoids with minor radius r and aspect ratio 20.2537, 0.2618, 0.250.3035, 0.29
Oblate ellipsoids with major radius r and aspect ratio 30.22890.2599
Prolate ellipsoids with minor radius r and aspect ratio 30.2033, 0.2244, 0.200.2541, 0.22
Oblate ellipsoids with major radius r and aspect ratio 40.20030.2235
Prolate ellipsoids with minor radius r and aspect ratio 40.1901, 0.160.2108, 0.17
Oblate ellipsoids with major radius r and aspect ratio 50.17570.1932
Prolate ellipsoids with minor radius r and aspect ratio 50.1627, 0.130.1776, 0.15
Oblate ellipsoids with major radius r and aspect ratio 100.0895, 0.10580.1118
Prolate ellipsoids with minor radius r and aspect ratio 100.0724, 0.08703, 0.070.09105, 0.07
Oblate ellipsoids with major radius r and aspect ratio 1000.012480.01256
Prolate ellipsoids with minor radius r and aspect ratio 1000.0069490.006973
Oblate ellipsoids with major radius r and aspect ratio 10000.0012750.001276
Oblate ellipsoids with major radius r and aspect ratio 20000.0006370.000637
Spherocylinders with H/D = 10.2439
Spherocylinders with H/D = 40.1345
Spherocylinders with H/D = 100.06418
Spherocylinders with H/D = 500.01440
Spherocylinders with H/D = 1000.007156
Spherocylinders with H/D = 2000.003724
Aligned cylinders0.28190.3312
Aligned cubes of side0.2773 0.27727, 0.277302610.3247, 0.3248, 0.32476
Randomly oriented icosahedra0.3030
Randomly oriented dodecahedra0.2949
Randomly oriented octahedra0.2514
Randomly oriented cubes of side0.2168 0.2174,0.2444, 0.2443
Randomly oriented tetrahedra0.1701
Randomly oriented disks of radius r 0.9614
Randomly oriented square plates of side0.8647
Randomly oriented triangular plates of side0.7295
Voids around disks of radius r22.86
Voids around oblate ellipsoids of major radius r and aspect ratio 1015.42
Voids around oblate ellipsoids of major radius r and aspect ratio 26.478
Voids around hemispheres0.0455
Voids around aligned tetrahedra0.0605
Voids around rotated tetrahedra0.0605
Voids around aligned cubes0.036, 0.0381
Voids around rotated cubes0.0381
Voids around aligned octahedra0.0407
Voids around rotated octahedra0.0398
Voids around aligned dodecahedra0.0356
Voids around rotated dodecahedra0.0360
Voids around aligned icosahedra0.0346
Voids around rotated icosahedra0.0336
Voids around spheres0.034, 0.032, 0.030, 0.0301, 0.0294, 0.0300, 0.0317, 0.0308 0.03013.506, 3.515
Jammed spheres 0.183, 0.1990, see also contact network of jammed spheres0.59

is the total volume, where N is the number of objects and L is the system size.
is the critical volume fraction.
For disks and plates, these are effective volumes and volume fractions.
For void, is the critical void fraction.
For more results on void percolation around ellipsoids and elliptical plates, see.
For more ellipsoid percolation values see.
For spherocylinders, H/D is the ratio of the height to the diameter of the cylinder, which is then capped by hemispheres. Additional values are given in.
For superballs, m is the deformation parameter, the percolation values are given in., In addition, the thresholds of concave-shaped superballs are also determined in
For cuboid-like particles, m is the deformation parameter, more percolation values are given in.

Thresholds on 3D random and quasi-lattices

LatticezSite percolation thresholdBond percolation threshold
Contact network of packed spheres60.310, 0.287, 0.3116,
Random-plane tessellation, dual60.290
Icosahedral Penrose60.2850.225
Penrose w/2 diagonals6.7640.2710.207
Penrose w/8 diagonals12.7640.1880.111
Voronoi network15.540.14530.0822

Thresholds for 3D correlated percolation

LatticezSite percolation thresholdBond percolation threshold
Drilling percolation, simple cubic lattice66*0.633965, 0.6339
, 6345

Continuum models in higher dimensions

dSystemΦcηc
4Overlapping hyperspheres0.12230.1304
4Aligned hypercubes0.1132, 0.11323480.1201
4Voids around hyperspheres0.002116.161
5Overlapping hyperspheres0.05443
5Aligned hypercubes0.04900, 0.0481621,0.05024
5Voids around hyperspheres1.26x10−4 8.98
6Overlapping hyperspheres0.02339
6Aligned hypercubes0.02082, 0.02134790.02104
6Voids around hyperspheres8.0x10−611.74
7Overlapping hyperspheres0.02339
7Aligned hypercubes0.00999, 0.00977540.01004
8Overlapping hyperspheres0.004904
8Aligned hypercubes0.004498
9Overlapping hyperspheres0.002353
9Aligned hypercubes0.002166
10Overlapping hyperspheres0.001138
10Aligned hypercubes0.001058
11Overlapping hyperspheres0.0005530
11Aligned hypercubes0.0005160

In 4d,.
In 5d,.
In 6d,.
is the critical volume fraction.
For void models, is the critical void fraction, and is the total volume of the overlapping objects

Thresholds on hypercubic lattices

dzSite thresholdsBond thresholds
480.198 0.197, 0.1968861, 0.196889, 0.196901, 0.19680, 0.1968904, 0.196885610.16005, 0.1601314, 0.160130, 0.1601310,, 0.1601312, 0.16013122
5100.141,0.198 0.141, 0.1407966, 0.1407966, 0.140796330.11819, 0.118172, 0.1181718 0.11817145
6120.106, 0.108, 0.109017, 0.1090117, 0.1090166610.0942, 0.0942019, 0.09420165
7140.05950, 0.088939, 0.0889511, 0.0889511, 0.088951121,0.078685, 0.0786752, 0.078675230
8160.0752101, 0.0752101280.06770, 0.06770839, 0.0677084181
9180.0652095, 0.06520953480.05950, 0.05949601, 0.0594960034
10200.0575930, 0.05759294880.05309258, 0.0530925842
11220.05158971, 0.05158968430.04794969, 0.04794968373
12240.04673099, 0.04673097550.04372386, 0.04372385825
13260.04271508, 0.042715079600.04018762, 0.04018761703

For thresholds on high dimensional hypercubic lattices, we have the asymptotic series expansions
where.

Thresholds in other higher-dimensional lattices

dlatticezSite thresholdsBond thresholds
4diamond50.29780.2715
4kagome80.27150.177
4bcc160.10370.074, 0.074212
4fcc240.0842, 0.084100.049, 0.049517
4cubic NN+2NN320.061900.035827
4cubic 3NN320.04540
4cubic NN+3NN400.04000
4cubic 2NN+3NN580.03310
4cubic NN+2NN+3NN640.03190
5diamond60.22520.2084
5kagome100.20840.130
5bcc320.04460.033
5fcc400.04310.026
6diamond70.17990.1677
6kagome120.1677
6fcc600.0252
6bcc640.0199

Thresholds in one-dimensional long-range percolation

In a one-dimensional chain we establish bonds between distinct sites and with probability decaying as a power-law with an exponent. Percolation occurs at a critical value for. The numerically determined percolation thresholds are given by:
0.10.047685
0.20.093211
0.30.140546
0.40.193471
0.50.25482
0.60.327098
0.70.413752
0.80.521001
0.90.66408

Thresholds on hyperbolic, hierarchical, and tree lattices

In these lattices there may be two percolation thresholds: the lower threshold is the probability above which infinite clusters appear, and the upper is the probability above which there is a unique infinite cluster.
Note: is the Schläfli symbol, signifying a hyperbolic lattice in which n regular m-gons meet at every vertex
For bond percolation on, we have by duality. For site percolation, because of the self-matching of triangulated lattices.
Cayley tree with coordination number z: pc = 1 /
Cayley tree with a distribution of z with mean, mean-square pc=

Thresholds for directed percolation

LatticezSite percolation thresholdBond percolation threshold
-d honeycomb1.50.8399316, 0.839933, of -d sq.0.8228569, 0.82285680
-d kagome20.7369317, 0.736931820.6589689, 0.65896910
-d square, diagonal20.705489, 0.705489, 0.70548522, 0.70548515,
0.7054852,
0.644701, 0.644701, 0.644701,
0.6447006, 0.64470015, 0.644700185, 0.6447001, 0.643
-d triangular30.595646, 0.5956468, 0.59564700.478018, 0.478025, 0.4780250 0.479
-d simple cubic, diagonal planes30.43531, 0.435314110.382223, 0.38222462 0.383
-d square nn 40.3445736, 0.344575 0.34457400.2873383, 0.287338 0.28733838 0.287
-d fcc0.199)
-d hypercubic, diagonal40.3025, 0.303395380.26835628, 0.2682
-d cubic, nn60.20810400.1774970
-d bcc80.160950, 0.160961280.13237417
-d hypercubic, diagonal50.231046860.20791816, 0.2085
-d hypercubic, nn80.1461593, 0.14615820.1288557
-d bcc160.075582
0.0755850, 0.07558515
0.063763395
-d hypercubic, diagonal60.186513580.170615155, 0.1714
-d hypercubic, nn100.11233730.1016796
-d hypercubic bcc320.035967, 0.0359725400.0314566318
-d hypercubic, diagonal70.156547180.145089946, 0.1458
-d hypercubic, nn120.09130870.0841997
-d hypercubic bcc640.0173330510.01565938296
-d hypercubic, diagonal80.1350041760.126387509, 0.1270
-d hypercubic,nn140.076993360.07195
-d bcc1280.008 432 9890.007 818 371 82

nn = nearest neighbors. For a -dimensional hypercubic system, the hypercube is in d dimensions and the time direction points to the 2D nearest neighbors.

Exact critical manifolds of inhomogeneous systems

Inhomogeneous triangular lattice bond percolation
Inhomogeneous honeycomb lattice bond percolation = kagome lattice site percolation
Inhomogeneous lattice, site percolation
or
Inhomogeneous union-jack lattice, site percolation with probabilities
Inhomogeneous martini lattice, bond percolation
Inhomogeneous martini lattice, site percolation. r = site in the star
Inhomogeneous martini-A lattice, bond percolation. Left side :. Right side:. Cross bond:.
Inhomogeneous martini-B lattice, bond percolation
Inhomogeneous martini lattice with outside enclosing triangle of bonds, probabilities from inside to outside, bond percolation
Inhomogeneous checkerboard lattice, bond percolation
Inhomogeneous bow-tie lattice, bond percolation
where are the four bonds around the square and is the diagonal bond connecting the vertex between bonds and.

For graphs

For random graphs not embedded in space the percolation threshold can be calculated exactly. For example, for random regular graphs where all nodes have the same degree k, pc=1/k. For Erdős–Rényi graphs with Poissonian degree distribution, pc=1/. The critical threshold was calculated exactly also for a network of interdependent ER networks.