Applying Bohr-Sommerfeld quantization and the topological phase of spin path
integrals, one can determine the multiplicities, lattice symmetries, and
eigenvalue clustering pattern of the low-lying singlet eigenstates of the
triangular and fcc antiferromagnets with 4-sublattice classical ground states.
In the triangular case, the clustering pattern agrees with numerical results of
Lecheminant et al (Phys. Rev. B 52, 6647 (1995)).Comment: 4 pages, 1 figure, 1 table. Clarifications, correction of
inconsistent notations, and citation of Bernu et al 199