A new ground state for b.c.c. Mn is found by an extension of the fixed-spin-moment procedure in total-energy band theory. The ground state for a magnetic unit cell with the CsCl structure is shown to be ferrimagnetic over a range of lattice constant slightly expanded from equilibrium. Over the same range, the antiferromagnetic state is shown to be unstable. Connections of the ferrimagnetic state to the complex structure of α-Mn are suggested. © 1989.