The existence of a second bound state of PsH that is electronically stable and also stable against positron annihilation by the normal 2? and 3? processes is demonstrated by explicit calculation. The state can be found in the So2,4 symmetries with the two electrons in a spin-triplet state. The binding energy against dissociation into the H(2p)+Ps(2p) channel was 7.03�0-4hartree. The dominant decay mode of the states will be radiative decay into a configuration that autoionizes or undergoes positron annihilation. The NaPs system of the same symmetry is also electronically stable with a binding energy of 1.514�0-3hartree with respect to the Na(3p)+Ps(2p) channel. � 2007 The American Physical Society.
|Number of pages||5|
|Journal||Physical Review Letters|
|Publication status||Published - 2007|