Negative Calcium Ions Are Stable—In Spite of the Conventional Wisdom
JUN 01, 1988
DOI: 10.1063/1.2811444
Most atomic species—roughly 80% of the periodic table—can form stable negative ions in their gaseous phase. The most notable and easily understood exceptions are the noble gas atoms, the symmetry of whose completely filled electron shells offers no handhold for a would‐be extra tenant. The alkaline earths—calcium, strontium, barium and their group IIA cousins—are similarly inhospitable, or so the standard textbooks assure us. Two back‐to‐back reports in a recent issue of Physical Review Letters have now disabused us of this venerable assurance.
© 1988. American Institute of Physics
