Acronym ike   (alt.: snit)
TOCID symbol I, sO, sTT
Name icosahedron,
snub tetrahedron,
snub tetratetrahedron,
hydrohedron
 
 © ©
Circumradius sqrt[(5+sqrt(5))/8] = 0.951057
Inradius sqrt[(7+3 sqrt(5))/24] = 0.755761
Vertex figure [35] = x5o
Snub derivation
Vertex layers
LayerSymmetrySubsymmetries
 o3o5oo3o .o . o. o5o
1x3o5ox3o .
{3} first
x . o
edge first
. o5o
vertex first
2o3f .o . f. x5o
vertex figure
3f3o .f . x. o5x
4o3x .
opposite {3}
o . f. o5o
opposite vertex
5 x . o
opposite edge
 
Lace city
in approx. ASCII-art
 o   o 
   f   
x     x
   f   
 o   o 
Coordinates (τ/2, 1/2, 0)   & even permutations, all changes of sign
where τ = (1+sqrt(5))/2
General of army (is itself convex)
Colonel of regiment (is itself locally convex – other uniform polyhedral member: gad – other edge facetings)
Dual doe
Confer
Grünbaumian relatives:
2ike   cid   ike+2gad   2ike+gad   ike+3gad   3ike+gad   4ike+gad   5ike+gad   2ike+4gad   4ike+2gad  
related Johnson solids:
peppy   gyepip   pap   mibdi   teddi  
blends:
2 pap blend  
compounds:
siddo   sne  
general polytopal classes:
deltahedra   regular  
External
links
hedrondude   wikipedia   WikiChoron   mathworld   Polyedergarten   quickfur

As abstract polytope ike is isomorphic to gike, thereby replacing vertex figure pentagons by corresponding pentagrams.


Incidence matrix according to Dynkin symbol

x3o5o

. . . | 12 |  5 |  5
------+----+----+---
x . . |  2 | 30 |  2
------+----+----+---
x3o . |  3 |  3 | 20

x3/2o5o

.   . . | 12 |  5 |  5
--------+----+----+---
x   . . |  2 | 30 |  2
--------+----+----+---
x3/2o . |  3 |  3 | 20

o5/4o3x

.   . . | 12 |  5 |  5
--------+----+----+---
.   . x |  2 | 30 |  2
--------+----+----+---
.   o3x |  3 |  3 | 20

o5/4o3/2x

.   .   . | 12 |  5 |  5
----------+----+----+---
.   .   x |  2 | 30 |  2
----------+----+----+---
.   o3/2x |  3 |  3 | 20

s3s3s

demi( . . . ) | 12 | 1  2  2 | 1 1  3
--------------+----+---------+-------
      s 2 s   |  2 | 6  *  * | 0 0  2
sefa( s3s . ) |  2 | * 12  * | 1 0  1
sefa( . s3s ) |  2 | *  * 12 | 0 1  1
--------------+----+---------+-------
      s3s .     3 | 0  3  0 | 4 *  *
      . s3s     3 | 0  0  3 | * 4  *
sefa( s3s3s ) |  3 | 1  1  1 | * * 12

or
demi( . . . )                   | 12 | 1  4 | 2  3
--------------------------------+----+------+-----
      s 2 s                     |  2 | 6  * | 0  2
sefa( s3s . )  &  sefa( . s3s ) |  2 | * 24 | 1  1
--------------------------------+----+------+-----
      s3s .    &        . s3s     3 | 0  3 | 8  *
sefa( s3s3s )                   |  3 | 1  2 | * 12

s3s4o

demi( . . . ) | 12 | 1  4 | 2  3
--------------+----+------+-----
      . s4o   |  2 | 6  * | 0  2
sefa( s3s . ) |  2 | * 24 | 1  1
--------------+----+------+-----
      s3s .     3 | 0  3 | 8  *
sefa( s3s4o ) |  3 | 1  2 | * 12

s3s4/3o

demi( . .   . ) | 12 | 1  4 | 2  3
----------------+----+------+-----
      . s4/3o   |  2 | 6  * | 0  2
sefa( s3s   . ) |  2 | * 24 | 1  1
----------------+----+------+-----
      s3s   .     3 | 0  3 | 8  *
sefa( s3s4/3o ) |  3 | 1  2 | * 12

oxoo5ooxo&#xt   → outer heights = sqrt((5-sqrt(5))/10) = 0.525731,
                  inner height  = sqrt((5+sqrt(5))/10) = 0.850651
(pt || pseudo {5} || dual pseudo {5} || pt)

o...5o...    | 1 * * * | 5 0  0 0 0 | 5 0 0 0
.o..5.o..    | * 5 * * | 1 2  2 0 0 | 2 2 1 0
..o.5..o.    | * * 5 * | 0 0  2 2 1 | 0 1 2 2
...o5...o    | * * * 1 | 0 0  0 0 5 | 0 0 0 5
-------------+---------+------------+--------
oo..5oo..&#x | 1 1 0 0 | 5 *  * * * | 2 0 0 0
.x.. ....    | 0 2 0 0 | * 5  * * * | 1 1 0 0
.oo. .oo.&#x | 0 1 1 0 | * * 10 * * | 0 1 1 0
.... ..x.    | 0 0 2 0 | * *  * 5 * | 0 0 1 1
..oo5..oo&#x | 0 0 1 1 | * *  * * 5 | 0 0 0 2
-------------+---------+------------+--------
ox.. ....&#x | 1 2 0 0 | 2 1  0 0 0 | 5 * * *
.xo. ....&#x | 0 2 1 0 | 0 1  2 0 0 | * 5 * *
.... .ox.&#x | 0 1 2 0 | 0 0  2 1 0 | * * 5 *
.... ..xo&#x | 0 0 2 1 | 0 0  0 1 2 | * * * 5

or
o...5o...    & | 2  * |  5  0  0 |  5  0
.o..5.o..    & | * 10 |  1  2  2 |  2  3
---------------+------+----------+------
oo..5oo..&#x & | 1  1 | 10  *  * |  2  0
.x.. ....    & | 0  2 |  * 10  * |  1  1
.oo. .oo.&#x   | 0  2 |  *  * 10 |  0  2
---------------+------+----------+------
ox.. ....&#x & | 1  2 |  2  1  0 | 10  *
.xo. ....&#x & | 0  3 |  0  1  2 |  * 10

xofo3ofox&#xt   → outer heights = 1/sqrt(3) = 0.577350
                  inner height = sqrt[(3-sqrt(5))/6] = 0.356822
({3} || pseudo dual f-{3} || pseudo f-{3} || dual {3})

o...3o...     | 3 * * * | 2 2 1 0 0 0 0 | 1 2 2 0 0 0
.o..3.o..     | * 3 * * | 0 2 0 2 1 0 0 | 0 1 2 2 0 0
..o.3..o.     | * * 3 * | 0 0 1 2 0 2 0 | 0 0 2 2 1 0
...o3...o     | * * * 3 | 0 0 0 0 1 2 2 | 0 0 0 2 2 1
--------------+---------+---------------+------------
x... ....     | 2 0 0 0 | 3 * * * * * * | 1 1 0 0 0 0
oo..3oo..&#x  | 1 1 0 0 | * 6 * * * * * | 0 1 1 0 0 0
o.o.3o.o.&#x  | 1 0 1 0 | * * 3 * * * * | 0 0 2 0 0 0
.oo.3.oo.&#x  | 0 1 1 0 | * * * 6 * * * | 0 0 1 1 0 0
.o.o3.o.o&#x  | 0 1 0 1 | * * * * 3 * * | 0 0 0 2 0 0
..oo3..oo&#x  | 0 0 1 1 | * * * * * 6 * | 0 0 0 1 1 0
.... ...x     | 0 0 0 2 | * * * * * * 3 | 0 0 0 0 1 1
--------------+---------+---------------+------------
x...3o...     | 3 0 0 0 | 3 0 0 0 0 0 0 | 1 * * * * *
xo.. ....&#x  | 2 1 0 0 | 1 2 0 0 0 0 0 | * 3 * * * *
ooo.3ooo.&#xt | 1 1 1 0 | 0 1 1 1 0 0 0 | * * 6 * * *
.ooo3.ooo&#xt | 0 1 1 1 | 0 0 0 1 1 1 0 | * * * 6 * *
.... ..ox&#x  | 0 0 1 2 | 0 0 0 0 0 2 1 | * * * * 3 *
...o3...x     | 0 0 0 3 | 0 0 0 0 0 0 3 | * * * * * 1

or
o...3o...      & | 6 * | 2  2 1 0 | 1 2  2
.o..3.o..      & | * 6 | 0  2 1 2 | 0 1  4
-----------------+-----+----------+-------
x... ....      & | 2 0 | 6  * * * | 1 1  0
oo..3oo..&#x   & | 1 1 | * 12 * * | 0 1  1
o.o.3o.o.&#x   & | 1 1 | *  * 6 * | 0 0  2
.oo.3.oo.&#x     | 0 2 | *  * * 6 | 0 0  2
-----------------+-----+----------+-------
x...3o...      & | 3 0 | 3  0 0 0 | 2 *  *
xo.. ....&#x   & | 2 1 | 1  2 0 0 | * 6  *
ooo.3ooo.&#xt  & | 1 2 | 0  1 1 1 | * * 12

xofox ofxfo&#xt   → outer heights = (sqrt(5)-1)/4 = 0.309017
                    inner heights = 1/2
(line || pseudo ortho f-line || pseudo (f,x)-{4} || pseudo ortho f-line || line)

o.... o....     | 2 * * * * | 1 2 2 0 0 0 0 0 0 0 | 2 2 1 0 0 0 0
.o... .o...     | * 2 * * * | 0 2 0 2 1 0 0 0 0 0 | 1 2 0 2 0 0 0
..o.. ..o..     | * * 4 * * | 0 0 1 1 0 1 1 1 0 0 | 0 1 1 1 1 1 0
...o. ...o.     | * * * 2 * | 0 0 0 0 1 0 2 0 2 0 | 0 0 0 2 2 0 1
....o ....o     | * * * * 2 | 0 0 0 0 0 0 0 2 2 1 | 0 0 0 0 2 1 2
----------------+-----------+---------------------+--------------
x.... .....     | 2 0 0 0 0 | 1 * * * * * * * * * | 2 0 0 0 0 0 0
oo... oo...&#x  | 1 1 0 0 0 | * 4 * * * * * * * * | 1 1 0 0 0 0 0
o.o.. o.o..&#x  | 1 0 1 0 0 | * * 4 * * * * * * * | 0 1 1 0 0 0 0
.oo.. .oo..&#x  | 0 1 1 0 0 | * * * 4 * * * * * * | 0 1 0 1 0 0 0
.o.o. .o.o.&#x  | 0 1 0 1 0 | * * * * 2 * * * * * | 0 0 0 2 0 0 0
..... ..x..     | 0 0 2 0 0 | * * * * * 2 * * * * | 0 0 1 0 0 1 0
..oo. ..oo.&#x  | 0 0 1 1 0 | * * * * * * 4 * * * | 0 0 0 1 1 0 0
..o.o ..o.o&#x  | 0 0 1 0 1 | * * * * * * * 4 * * | 0 0 0 0 1 1 0
...oo ...oo&#x  | 0 0 0 1 1 | * * * * * * * * 4 * | 0 0 0 0 1 0 1
....x .....     | 0 0 0 0 2 | * * * * * * * * * 1 | 0 0 0 0 0 0 2
----------------+-----------+---------------------+--------------
xo... .....&#x  | 2 1 0 0 0 | 1 2 0 0 0 0 0 0 0 0 | 2 * * * * * *
ooo.. ooo..&#xt | 1 1 1 0 0 | 0 1 1 1 0 0 0 0 0 0 | * 4 * * * * *
..... o.x..&#x  | 1 0 2 0 0 | 0 0 2 0 0 1 0 0 0 0 | * * 2 * * * *
.ooo. .ooo.&#xt | 0 1 1 1 0 | 0 0 0 1 1 0 1 0 0 0 | * * * 4 * * *
..ooo ..ooo&#xt | 0 0 1 1 1 | 0 0 0 0 0 0 1 1 1 0 | * * * * 4 * *
..... ..x.o&#x  | 0 0 2 0 1 | 0 0 0 0 0 1 0 2 0 0 | * * * * * 2 *
...ox .....&#x  | 0 0 0 1 2 | 0 0 0 0 0 0 0 0 2 1 | * * * * * * 2

or
o.... o....      & | 4 * * | 1 2 2 0 0 0 | 2 2 1 0
.o... .o...      & | * 4 * | 0 2 0 2 1 0 | 1 2 0 2
..o.. ..o..        | * * 4 | 0 0 2 2 0 1 | 0 2 2 1
-------------------+-------+-------------+--------
x.... .....      & | 2 0 0 | 2 * * * * * | 2 0 0 0
oo... oo...&#x   & | 1 1 0 | * 8 * * * * | 1 1 0 0
o.o.. o.o..&#x   & | 1 0 1 | * * 8 * * * | 0 1 1 0
.oo.. .oo..&#x   & | 0 1 1 | * * * 8 * * | 0 1 0 1
.o.o. .o.o.&#x     | 0 2 0 | * * * * 2 * | 0 0 0 2
..... ..x..        | 0 0 2 | * * * * * 2 | 0 0 2 0
-------------------+-------+-------------+--------
xo... .....&#x   & | 2 1 0 | 1 2 0 0 0 0 | 4 * * *
ooo.. ooo..&#xt  & | 1 1 1 | 0 1 1 1 0 0 | * 8 * *
..... o.x..&#x   & | 1 0 2 | 0 0 2 0 0 1 | * * 4 *
.ooo. .ooo.&#xt    | 0 2 1 | 0 0 0 2 1 0 | * * * 4

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