Potential-Energy Curves for the X 1Σg+, b3Σu+, and C 1Πu States of the Hydrogen Molecule

Abstract

Previous calculation of the ground-state energy of H2 has been extended to include large internuclear distances and accurate potential-energy curve for 0.4≤R≤10.0 a.u. is presented. For 0.4≤R≤4.0 a.u. expectation values of several operators have also been calculated. The calculation was made using a wavefunction in the form of an expansion in elliptic coordinates. The wavefunction depends on the interelectronic distance but, in contrast to the James—Coolidge expansion, is flexible enough to describe properly the dissociation of the molecule. Extensive calculations have also been made for the repulsive 3Σu+ state (1.0≤R≤10.0) and for the 1Πu state (1.0≤R≤10.0). In the former case a van der Waals minimum has been found at R=7.85 a.u. and 4.3 cm−1 below the dissociation limit. For the 1Πu state the computed binding energy De=20 490.0 cm−1 and the equilibrium internuclear distance Re=1.0330 Å are in a satisfactory agreement with the experimental values De=20 488.5 cm−1 and Re=1.0327 Å. In this case a van der Waals potential maximum has been found to occur at R=9.0 a.u. and 105.5 cm−1 above the dissociation limit. Preliminary results for the 1Σu+ state at R≈Re are also given.

Abinitiopotential-energy surfaces and electron-spin-exchange cross sections for H-O2interactions

“…Accurate interaction energies [3,4] have allowed accurate calculations [5][6][7] of the spin-flip cross sections for the collision of hydrogen atoms; the theoretical results agree well with measured data [8]. On the other hand, the comparison for H-O 2 is considerably less satisfactory; spin-flip-scattering calculations with accurate interaction energies have been recommended [9,10] to help resolve differences in measured data.…”

Calculations of the binding energies of weakly bound He-He-H, He-He-H-and He-H-H molecules

“…The He-H pair interaction is shown in figure 1 and the H-H interaction is given by the BornOppenheimer potential of the ground state of H 2 [32]. The ground vibrational level of H 2 has a binding energy of −4.4774 eV.…”

Evolution and colors of helium-core white dwarf stars with high-metallicity progenitors

“…Broadening of Lyα line by H-H collisions plays a minor role compared to H-H 2 encounters. The potential interactions for H-H configurations were taken from Kolos & Wolniewicz (1965) and the transition probability was assumed constant in this case. The main effect of the Lyα quasi-molecular opacity is a reduction of the predicted flux at wavelength smaller than 5000 Å for white dwarfs cooler than T eff ≈ 6000 K.…”