Exchange and correlation energies of ground states of atoms and molecules in strong magnetic fields

摘要

Using a Hartree-Fock mesh method and a configuration interaction approachbased on a generalized Gaussian basis set we investigate the behaviour of theexchange and correlation energies of small atoms and molecules, namely th ehelium and lithium atom as well as the hydrogen molecule, in the presence of amagnetic field covering the regime B=0-100a.u. In general the importance of theexchange energy to the binding properties of at oms or molecules increasesstrongly with increasing field strength. This is due to the spin-fliptransitions and in particular due to the contributions of the tightly boundhydrogenic state s which are involved in the corresponding ground states ofdifferent symmetries. In contrast to the exchange energy the correlation energybecomes less relevant with increasing field strength. This holds for theindividual configurations constituting the ground state and for the crossoversof the global ground state.