  T-odd P-even long-range electromagnetic interaction of a particle of spin 1/2
with the nucleus is considered. Though matrix element of the interaction is
zero for the particles on mass shell, nevertheless, null test exists for the
interaction. The test consists in measuring of the spin-dependent T-odd P-even
forward elastic scattering amplitude of a particle of spin 1/2 by atomic chain
(axis) in a crystall.
