Desmic Surface
Let 
, 
, and 
be tetrahedra in projective 3-space 
. Then the tetrahedra are said to bedesmically related if there exist constants 
, 
, and 
such that
A desmic surface is then defined as a Quartic Surface which can be written as
for desmically related tetrahedra
, , and . Desmic surfaces have 12 Ordinary DoublePoints, which are the vertices of three tetrahedra in 3-space (Hunt).See also Quartic Surface
References
Hunt, B. ``Desmic Surfaces.'' §B.5.2 in The Geometry of Some Special Arithmetic Quotients. New York: Springer-Verlag, pp. 311-315, 1996. Jessop, C. §13 in Quartic Surfaces with Singular Points. Cambridge, England: Cambridge University Press, 1916.
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