Calculation of potential energy curves for the ground state of the hydrogen molecule

Potential energy curves for the X1σ g + state of H2 are calculated from three wave functions which, in spite of their conceptual simplicity, yield results of remarkable accuracy. The three functions yield 87·06, 91·07 and 93·14 per cent of the observed binding energy, and provide an accurate description of the system over a wide range of nuclear separations. The fundamental vibration frequency is calculated for each curve, and the long-range behaviour of the wave functions is examined.