The Tamm-Dancoff method is applied to the calculation of the electrostatic properties of the deuteron. The state vector is assumed to contain amplitudes for at most two mesons in the field, but the possible presence of nucleon-antinucleon pairs is ignored. A formula applicable to the calculation of any multipole moment is derived and used to compute the leading exchange corrections, of order $g^2$ and $g^4$, respectively, to the usual expression for the quadrupole moment. For a suitably chosen hard-core wave function the ratio of successive terms is about one tenth, and the $g^2$ term is itself only a few percent of the total effect.

• Received 27 April 1955

DOI:https://doi.org/10.1103/PhysRev.99.966