New‐type correlated wavefunctions for three‐body systems with Coulomb interaction

Simple correlated wavefunctions are reported for the ground states of three selected Coulombic systems, namely (1) the positronium negative ion e−e+e−, (2) the hydrogen negative ion H−, and (3) the mesic molecular ion pμp. They give quite accurate energy results, and are analytically simple enough to be used widely in applications. Two characteristic features of the proposed wavefunctions are that (1) the correlation between the two particles with the same sign of the charge is explicitly included in the form G= xn3e−γx3, and (2) the variational parameters to be optimized are mostly nonlinear (exponential).