The symplectic group for Even is the Group of elements of the General Linear Group that preserve a given nonsingular Symplectic Form. Any such Matrix has Determinant 1.
See also General Linear Group, Lie-Type Group, Projective Symplectic Group, Symplectic Form
References
Conway, J. H.; Curtis, R. T.; Norton, S. P.; Parker, R. A.; and Wilson, R. A.
``The Groups and
.'' §2.3 in
Atlas of Finite Groups: Maximal Subgroups and Ordinary Characters for Simple Groups. Oxford, England:
Clarendon Press, pp. x-xi, 1985.
Wilson, R. A. ``ATLAS of Finite Group Representation.''
http://for.mat.bham.ac.uk/atlas/html/contents.html#symp.