Electronic and vibrational properties of molecules at high pressures. Hydrogen molecule in a rigid spheroidal box

A variational calcuation employing a five-term James-Coolidge wave function is presented for a hydrogen molecule enclosed within an infinte-walled spheroidal box. Properties examined include the pressure dependence of the equilibrium bond length, the vibrational force constant, the total energy, the ionization potential, the electronic kinetic energy, and the electronic correlation energy. Comparison is made with similar calculations for the H2+ molecular ion and the He and H atoms. A Badger's rule correlation of force constant and bond length is found to hold over a wide pressure range. Comparisons with the available experimental results show that generally the rigid-box model greatly exaggerates the effects of compression