A new variational approach to muonic molecules is proposed. The total three-body wave function is expanded in terms of basis functions spanned over the three rearrangement channels in the Jacobian coordinate system. Energy levels of the dtμ molecule are calculated with a high accuracy and a short computation time. For the weakly bound state with J=v=1, which is a key to the muon-catalyzed d-t fusion, the calculated energy ${\varepsilon }_{11}$ is better than the literature data. With the use of the most up-to-date, 1986 CODATA–recommended [E. R. Cohen and B. N. Taylor, CODATA Bull. 63 (1986)] values of physical constants, we obtained ${\varepsilon }_{11}$=-0.660 264 eV with 2662 basis functions and ${\varepsilon }_{11}$(∞)=-0.66030±000 02 eV by extrapolation.

• Received 21 December 1987

DOI:https://doi.org/10.1103/PhysRevA.38.621