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Heavy elemental compounds

Heavy elements are of particular interest to us because many of the highly exciting molecular properties, such as parity violating (P-odd) effects or parity and time reversal symmetry violating (P,T-odd) effects increase strongly with the nuclear charge number Z. If one wants to thus advantageously explore the limits of the current standard model, one must strive for the heaviest elements in the periodic table.

The best upper bounds for a P,T-violating electric dipole moment of the electron currently originate from spectroscopic experiments on the diatomic ThO (and interestingly enough not from high-energy experiments). Due to the laser coolability we consider the diatomic RaF as a promising candidate to improve existing limits.

Recently, we have proposed to use chiral molecules for the possible detection of hypothetical P-odd cosmic field interactions. And here especially chiral compounds of heavy elements play a decisive role due to advantageous Z-scaling.

And apart from the search for violations of fundamental symmetries, heavy elements are of general interest due to the increase of relativistic effects such as spin-orbit coupling. This may, for example, cause fundamental changes in the bonding situation or cause qualitative changes in molecular properties. This renders the theoretical prediction of such properties particularly exciting.