The parametric dependence of the eigenvalue of the Hamiltonian on the
particle masses and precision values calculated for 45 reference syste
ms within the variational approach implemented for the basis of Laguer
re functions of perimetric particle coordinates are used to construct
explicit formulas that determine the energies of the ground states of
all three-particle Coulomb systems X+/-X+/-Y-/+ (symmetric trions) con
sisting of singly charged particles X+/- and Y-/+ with arbitrary masse
s. These formulas can be applied to any symmetric three-particle atomi
c, molecular, and mesic molecular systems and to electron-hole systems
in solids. The energies of the ground states of 63 symmetric trions c
orresponding to all possible combinations of electrons, positrons, muo
ns, pions, kaons, and hydrogen nuclei and antinuclei are calculated on
the basis of these formulas.