Hydrogen molecular ion in the magnetic field of a neutron star. I: Two-dimensional potential surface

A two-dimensional potential energy surface of an H2(+) molecular ion is calculated for the case of the strong magnetic field of the neutron star B = 10 to the 11th-10 to the 13th G. It is shown that the dependence of the potential energy from the angle between the magnetic field direction and the internuclear axis becomes very sharp as the magnetic field increases. The obtained potential energy surfaces can be used for studying the vibrational-rotational structure of the H2(+) spectrum in a strong magnetic field and the development of the observational methods for the determination of the magnetic field of a neutron star.