Double-Rydberg molecular anions

On the Possibility of Mixed Rydberg-Valence Bonds

“…The electron binding energy of the NH 4 orbital (4 eV 8 ) is lower than that of 3s Na (5.1 eV 8 ), and the vertical electron affinity of NH 4 (0.42 eV 8 ) is smaller than that of Na (0.72 eV 8 ), so the Mulliken electronegativity of Na is expected to be approximately 5.82/4.42 ) 1.3 times that of NH 4 . Hence, the bonding in the (NH 4 )Na species studied here is expected to be covalent and polar but not ionic.…”

Chapter 8 Electron Transfer in Gaseous Positively Charged Peptides — Relation to Mass Spectrometry

“…2. The positively charged site to which an electron is to attach must have special basis functions [4][5][6] attached to it to describe the Rydberg orbitals. This is important because one needs to accurately describe the energies of the Rydberg states in relation to bond-attached states and the Rydberg orbitals' radial extent must be properly represented.…”

“…-122 QSAR/QSPR models, 1, 133-151 quantum electrodynamics (QED), 3, 155 quantum mechanics, 1, 3-56 basis sets, 1, 13-15, 32, 33 bond breaking, 1, 45-56 computational thermochemistry, 1, 31-43 configurational interaction, 1, 9, 10, 48, 51 coupled cluster methods, 1, 10, 11, 37-40, 48-50, 52, 53 density functional theory, 1, 4,11,12,[13][14][15]32,33,48,49 electron correlation methods,1,[8][9][10][11]1,47,1,4,[5][6][7][8][9][10][11][13][14][15]20,21,46, 48-51 perturbation theory, 1, 10, 51, 52 potential energy surface, 1, 3, 4, 54 self-consistent field methods, 1, 6-10, 37, 46, 47 Runge-Gross theorem, 1, 27 Rydberg orbital, 5,[165][166][167][168][170][171][172][173][174][175][176][177][178] …”

A strongly bound OF3- anion and its unstable parent neutral OF3 species

“…The HOMO holding the excess electron in the OF À 3 does not resemble the HOMOs of the DR anions either (the HOMO for the OF À 3 anion indicates substantial contributions from the p-symmetry fluorine AOs and it seems much more compact than a typical diffuse Rydberg-like orbital). In addition, the DR anions are known to possess their excess electron binding energies in the 0.08-0.95 eV range [19,20] whereas the VDE predicted for the OF À 3 is 5.534 eV and this value is much closer to the energy gain of an electron attachment to the cationic core (such as NH þ 4 or H 3 O + ) rather than the DR anion's VDE.…”

“…On the other hand, one might be tempted to classify the OF À 3 anion as a Double-Rydberg (DR) anionic state (similarly to the NH À 4 ) [19,20]. However, such states are not known to represent the global minima (in each H-containing DR anion, the 'solvated' H À complex is lower in energy, e.g., the NH À 4 anion is less stable than the H À /NH 3 complex) [19][20][21]. If the OF À 3 anion exhibited such characteristic, the OF À 3 ?…”