Configuration-interaction calculations on the 3s23pn configuration of neutral phosphorus and two of its ions

Frozen-Core versus Fully-Correlated Configuration Interaction on the Ground and Lowest Excited States of N+ and N

“…According to recently published results [1] on phosphorus and two of its ions, both P and P + possess an electronic structure similar to N and N + , respectively. A relativistic correction contribution to the excitation energy EE( 1 D 2 − 3 P 0 ) of P + is reported to be 344 cm −1 .…”

“…A comparison of both nonrelativistic valence and total energies in Tables V and VI, respectively, reveals that the fully-correlated CI calculations yield an estimation for excitation energy closer to the experiment than the frozen-core approximation by about 41 cm −1 . However, even with taking core-correlation and core-valence contributions [1] into account, the nonrelativistic theory is not always sufficient to achieve better agreement with the experiment. The relativistic effect is expected to be rigorous.…”

“…Recently, one of us [1] has calculated excitation energies, ionization potential, and binding energies related to the ground state and the two lowest excited states belonging to P + , P, and P − , using nonrelativistic and relativistic configuration interaction (CI) method. From both chemical and physical points of view, both N and P have the same ns 2 np 3 valence shell electron configuration and, consequently, the same term multiplet.…”