Fleming and coworkers reported in 2011 the measurements of reactions rates for the collision between a muonic helium atom and a hydrogen molecule. In this study they found that a mounic helium atom chemically behaved as a heavy isotope of hydrogen.

Inspired by this finding, we studied atoms containing 1 and 2 muons with the non-relativistic Any Particle Molecular Orbital (APMO) method. We found that properties such as electronic densities and ionization potentials shift to those of atoms with atomic numbers Z-1 and Z-2.

Our study reveals that the electronic properties of an atom are transmuted when one of its electrons is replaced by a negative muon.