  The finite dimensional simple modular Lie algebras with Cartan matrix cannot
be deformed if the characteristic p of the ground field is equal to 0 or
greater than 3. If p=3, the orthogonal Lie algebra o(5)is one of the two simple
modular Lie algebras with Cartan matrix that have deformations (the Brown
algebras br(2; a) are among these 10-dimensional deforms and hence are not
counted separately); the 29-dimensional Brown algebra br(3) is the only other
simple Lie algebra with Cartan matrix that has deformations. Kostrikin and
Kuznetsov described the orbits (isomorphism classes) under the action of the
group O(5) of automorphisms of o(5) on the space H^2(o(5);o(5)) and produced
representatives of the isomorphism classes. Here we explicitly describe global
deforms of o(5) and of the simple analog of this orthogonal Lie algebra in
characteristic 2.
