Accurate magnetizabilities of the isoelectronic series BeH−, BH, and CH+. The MCSCF-GIAO approach Original Research Article

We present the first calculations of molecular magnetizabilities using London atomic orbitals at the multiconfigurational self-consistent field level. The natural connection is introduced to ensure a numerically stable evaluation of the magnetizability. Furthermore, the natural connection enables us to study the paramagnetic and diamagnetic contributions to the total magnetizability using London atomic orbitals. Large MCSCF calculations are presented for the isoelectronic series BeH−, BH and CH+, for which correlation is known to be important. The geometry dependence of the magnetizability is investigated and shown to be small. It is demonstrated that BeH− is diamagnetic, contrary to the prediction of a recent study. Our calculated magnetizabilities for the three molecules are: (204–207) × 10−30 J T−2 (BH), (313–318) × 10−30 J T−2 (CH+), and (−62 ± 5) × 10−30 J T−2 BeH−).