Welcome to the Qcumbre website

QCUMBRE is a quantum-chemical program for computations of atoms and molecules in finite magnetic fields. It is hence capable of dealing with complex wave function parameters and integrals. The main emphasis is the accurate treatment of electron-correlation using Coupled Cluster methods, as well as treatment of excited states via various flavours of Equation of Motion-CC (Excitation Energy, Ionisation Potential, Electron Affinity, Spin Flip).

The program was initiated by Florian Hampe during his PhD (2015-2019) in the group of Stella Stopkowicz at the Johannes Gutenberg-University of Mainz. The authors aspire to contribute in the understanding of atoms and molecules in strong magnetic fields. In particular, one intended application is the prediction of magnetic white dwarf-spectra, where the strength of the magnetic field lies in a regime where a finite-field treatment is required (up to 100 000 T). In such strong fields where Lorentz and Coulomb forces compete, the chemistry of atoms and molecules changes in drastic and non-intuitive manners which makes the applications particularly fascinating.