We study certain lattices constructed from finite abelian groups. We show
that such a lattice is eutactic, thereby confirming a conjecture by B\"ottcher,
Eisenbarth, Fukshansky, Garcia, Maharaj. Our methods also yield simpler proofs
of two known results: First, such a lattice is strongly eutactic if and only if
the abelian group has odd order or is elementary abelian. Second, such a
lattice has a basis of minimal vectors, except for the cyclic group of order 4.Comment: v2: Minor corrections due to referee reports, 14 page