  Building on the fundamentals introduced in part I, we employ the Bethe ansatz
to study some ground-state properties (energy, magnetization, susceptibility)
of the one-dimensional s=1/2 Heisenberg antiferromagnet in zero and nonzero
magnetic field. The 2-spinon triplet and singlet excitations from the
zero-field ground state are discussed in detail, and their energies are
calculated for finite and infinite chains. Procedures for the numerical
calculation of real and complex solutions of the Bethe ansatz equations are
discussed and applied. The paper is designed as a tutorial for beginning
graduate students. It includes 10 problems for further study.
