@article{3051614,
    title = "The helium atom in a strong magnetic field",
    author = "Becken, W and Schmelcher, P and Diakonos, FK",
    journal = "Journal of Physics B: Atomic, Molecular and Optical Physics",
    year = "1999",
    volume = "32",
    number = "6",
    pages = "1557-1584",
    publisher = "IOP Publishing Ltd",
    issn = "0953-4075, 1361-6455",
    doi = "10.1088/0953-4075/32/6/018",
    abstract = "We investigate the electronic structure of the helium atom in a magnetic
field between B = 0 and 100 au. The atom is treated as a nonrelativistic
system with two interacting electrons and a fixed nucleus. Scaling laws
are provided connecting the fixed-nucleus Hamiltonian to the one for the
case of finite nuclear mass. Respecting the symmetries of the electronic
Hamiltonian in the presence of a magnetic field, we represent this
Hamiltonian as a matrix with respect to a two-particle basis composed of
one-particle states of a Gaussian basis set. The corresponding
generalized eigenvalue problem is solved numerically, providing results
for vanishing magnetic quantum number M = 0 and even or odd z-parity,
each for both singlet and tripler spin symmetry. Total electronic
energies of the ground state and the first few excitations in each
subspace as well as their one-electron ionization energies are presented
as a function of the magnetic field, and their behaviour is discussed.
Energy values for electromagnetic transitions within the M = 0 subspace
are shown, and a complete table of wavelengths at all the detected
stationary points with respect to their field dependence is given,
thereby providing a basis for a comparison with observed absorption
spectra of magnetic whits dwarfs."
}