The hartree-fock and the correlation energies of the H-3(+) ion and their dependence on the nuclear configuration

The method of solving the two-electron Schrodinger equation numerically by effect calculation of approximate natural orbitals is applied to the H-3(+) ion for different nuclear configurations, using a basis of Gaussian lobe functions. For the equilateral triangular equilibrium configuration and the lowest-energy linear configuration total energies of -1.3359 and -1.2729 a.u. respectively are obtained. the accurate eigenvalues can be estimated to be -1.341 +/- 0.001 and -1.278 +/- 0.001 a.u. Most striking is the change in the correlation energy, which has been calculated to be -0.039 a.u. in the triangular and -0.047 a.u. in the linear configuration.