Two papers published back-to-back in Journal of Chemical Physics by members of the Hylleraas Centre were both promoted as Editor's Pick by the editors of Journal of Chemical Physics: Ab initio molecular dynamics with screened Lorentz forces. I. Calculation and atomic charge interpretation of Berry curvature by Tanner Culpitt, Laurens D. M. Peters, Erik I. Tellgren* and Trygve Helgaker [J. Chem. Phys., 155, 024104 (2021)] and Ab Initio molecular dynamics with screened Lorentz forces. II. Efficient propagators and rovibrational spectra in strong magnetic fields by Laurens D. M. Peters*,Tanner Culpitt, Laurenz Monzel, Erik I. Tellgren, and Trygve Helgaker [J. Chem. Phys., 155, 024105 (2021)].
Together, the two papers report the first ab initio molecular dynamics calculations of molecules in a magnetic field, with integration of the classical equations of motion of the molecule in the presence of the Lorentz force. The two papers overcome several challenges to such calculations. First, the gauge-invariant ab initio calculation of the effective magnetic field acting on the nuclei, taking into account the screening of the external field by the electrons in the molecule. Second, the propagation of the classical equations of motion in the presence of the velocity-dependent Lorentz force. As an illustration, the vibrational spectrum of H2 in the presence of a magnetic field was calculations, providing the first glimpse into the complicated rovibrational spectra of molecules in a magnetic field.
The study of molecular dynamics in a magnetic field has been carried out within Research Theme 4: Extreme Environments at the Hylleraas Centre and is supported by Research Council of Norway through the FRIPRO project Magnetic Chemistry.