Helium trimer bound states are calculated by means of a variational method
described in terms of atom pair coordinates and distributed Gaussian basis
functions for zero total angular momentum. To show the feasibility of this
method, we also apply it to the calculation of the first vibrational levels
of the Ar-3 and Ne-3 clusters. Special emphasis is made on the study of th
e possible Efimov behavior of the first excited state found in the He-4(3)
trimer. Geometrical configurations of the ground and first excited states o
f these rare gas trimers have been exhaustively studied owing to the proper
symmetry of the coordinates chosen. (C) 1999 American Institute of Physics
. [S0021-9606(99)00218-4].