Acronym  sirsid 
TOCID symbol  s*IID* 
Name 
small (inverted) retrosnub icosicosidodecahedron, retrosnub disicosidodecahedron, yog sothoth 
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Circumradius  sqrt[13+3 sqrt(5)sqrt[102+46 sqrt(5)]]/4 = 0.580695 
Coordinates 

Vertex figure  [3/2,3,3/2,3,5/2,3] 
Colonel of regiment  (is itself not locally convex, but no other uniform polyhedral members) 
External links 
As abstract polytope sirsid is isomorphic to seside, thereby replacing retrograde icosahedral triangles by prograde ones. – As such sirsid is a lieutenant.
As mere alternated faceting the 2{3}compound is regular, for sure. It is by the afterwards to be applied step back to equally sized edges that those compounds become nonregular.
Incidence matrix according to Dynkin symbol
s3/2s3/2s5/2*a demi( . . . )  60  2 2 2  1 1 1 3 +++ sefa( s3/2s . )  2  60 * *  1 0 0 1 sefa( s . s5/2*a )  2  * 60 *  0 1 0 1 sefa( . s3/2s )  2  * * 60  0 0 1 1 +++ s3/2s . ♦ 3  3 0 0  20 * * * s . s5/2*a ♦ 5  0 5 0  * 12 * * . s3/2s ♦ 3  0 0 3  * * 20 * sefa( s3/2s3/2s5/2*a )  3  1 1 1  * * * 60 starting figure: x3/2x3/2x5/2*a
β3/2β5o both( . . . )  60  4 2  2 1 3 +++ sefa( s3/2s . )  2  120 *  1 0 1 sefa( . β5o )  2  * 60  0 1 1 +++ both( s3/2s . ) ♦ 3  3 0  40 * * as coplanar pair of {3} . β5o ♦ 5  0 5  * 12 * sefa( β3/2β5o )  3  2 1  * * 60 starting figure: x3/2x5o
or both( . . . )  60  4 2  2 1 3 +++ sefa( s3/2s . )  2  120 *  1 0 1 sefa( . β5o )  2  * 60  0 1 1 +++ both( s3/2s . ) ♦ 6  6 0  20 * * as nonregular compound of 2{3} . β5o ♦ 5  0 5  * 12 * sefa( β3/2β5o )  3  2 1  * * 60
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