Double Rydberg states

Double Rydberg states (double because both electrons are running electrons in this case) and the symmetrical double-ionisation problem were considered first by Wannier [320], and so the completely symmetric excited states with i = I2 and nj = ri2 as the double-ionisation threshold is approached are called Wannier states. These states have very interesting... 

J. Boulmer, P. Camus, P. Pillet, Autoionizing double Rydberg states in barium, in Electronic and Atomic Collisions, ed. by H.B. Gilbody, W.R. Newell, F.H. Read A.C. Smith (Elsevier, Amsterdam, 1988)... 

K. Yamanouchi Recently, we investigated the interatomic potential VRyd(/ ) of the Rydberg states of a HgNe van der Waals dimer by optical-optical double-resonance spectroscopy. It was demonstrated that VRyd(/ ) sensitively varies as a function of the principal quantum number n [J. Chem. Phys., 98, 2675 (1993) ibid., 101, 7290 (1995) ibid., 102, 1129 (1995)], and in the lowest Rydberg states of Hg(7 3S )Ne and Hg(7 5o)Ne, the interatomic potentials exhibit a distinct barrier at around R 4 A. The existence of the barrier was interpreted in terms of a repulsive interaction caused by the Is Rydberg... 

Ab initio calculations were carried out for all the low-lying non-Rydberg states of the systems N2, 02, NO, Of, and NO+. In N2, for example, there are 102 molecular states that result from nitrogen atoms in the lowest 4S, 2D, and 2P states. These states were all uniformly described using VCI wave functions constructed as described in Section II. Minimum basis, double-f basis and double-f-plus-polarization basis sets were employed for these studies. For the minimum basis-set calculations, which were always carried out first, the VCI wave functions represent full Cl projections with the constraint that the K shells were kept frozen for all states. However, no constraint on the 2og and 2ou orbitals was made since a Cl among these orbitals is necessary to ensure proper description of the hole states in these molecules, such as C3n of N2. The calculations all have the property of asymptotically connecting with the correct atomic states. This computational method has previously been applied, with reliable results, to both closed- and open-shell systems.6 9 11... 

The reaction profile that is displayed in the figures demonstrates the presence of a considerable barrier to the rearrangement of NH4 from a tetrahedral, double Rydberg structure to an anion-molecule complex. In the TS, C3v symmetry applies as one of the NH distances is markedly longer than the others. An additional reduction of symmetry occurs after the transition state with the formation of the hydride-ammonia complex. 

Fig. 7.7. Partial energy level diagram for Ca, showing the relative positions of the singly-excited high Rydberg states and the double excitations near the first ionisation potential (after H.E. White [26]).

The nonradiative decay pathways for the (X2E+ )np Rydberg states of H2 have been examined by McCormack, et al, (1993). Selected vibrational-rotational levels of the E, FXE+ state were excited by two-photon transitions from the X E+ state and the ungerade Rydberg states were examined by a double resonance excitation scheme via the selected levels of the E, F state. 

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