Positron binding to calcium, a configuration interaction study

The configuration interaction (CI) method is applied to the study of the po sitron-calcium system. A large basis CI investigation shows that positronic calcium, e(+)Ca, is stable with a binding energy of 0.220 eV and an annihi lation rate of 0.64 x 10(9) s(-1). The stability of e(+)Ca suggests that th e heavier group it elements could also bind a positron, and positron bindin g to strontium can be regarded as highly likely. The possibility of experim ental detection is discussed.