Valence–Rydberg electronic states of N₂: spectroscopy and spin–orbit couplings

Abstract

Using an ab initio methodology, we compute the potential energy curves and the spinorbit coupling integrals of the N 2 electronic states located in the 0-120000 cm -1 energy domaine.In our analysis, we focus mostly on those located outside the Franck-Condon regio n accessible from the ground state of N 2 i.e. the two strongly bound states 1 3 Σ g -and 1 1 Γ g , and the weakly bound state 2 3 Σ g -, in addition to several repulsive states. We characterize them spectroscopically and we compute their spin-orbit couplings to the close lying singlets, triplets and quintets. This work completes our knowledge on the electronic states of N 2 that may be important intermediates during N + N collisions and for the dynamics of the N 2 singlets and triplets and quintets VUV photodissociation.

Indirect predissociation of highly excited singlet states of N2

“…The predissociation linewidths of the b [28,34,35]. Additionally, the rapid increase of b (20) linewidths for J > 0 suggests a rotationaluncoupling mechanism [46] and is more difficult to explain.…”

“…Ab initio calculations [34,35] show multiple ungerade triplet levels dissociating to N( 4 S) + N( 4 P ) which may provide a further spin-orbit mediated mechanism for 1 u predissociation, but this has yet to be quantified. Optically-allowed ground-state excitation into a continuum is finally allowed for transitions into the b In this paper, we have quantified an accidental predissociation mechanism for the highly-excited state b…”

“…The ab initio calculations of electronic wavefunctions, (r; R), in the adiabatic approximation of motionless nuclei are within the reach of modern quantum chemistry, and have been performed for many excited states of N 2 [17,34,35,47]. Then, a reduction of the full calculated electronic wavefunctions to diabatic potential-energy curves, V (R), such as those in Fig.…”

Computed bound and continuum electronic states of the nitrogen molecule

“…This crossing is the result of the interaction between the n = 4 Rydberg state and the valence state. In practice, one has to work very hard to use quantum chemistry packages such as MOLPRO to characterise even energetically low-lying regions containing Rydberg-valence crossings as attested by the very careful but limited study of Spelsberg and Meyer [30] and the more complete but less accurate studies of Hochlaf et al [31,32]. .…”

Distickstoff als doppelte Lewis‐Säure: Struktur und Bindung von Triphenylphosphinazin N2(PPh3)2

“…Ab-initio-Rechnungen auf hohem Niveau sagen einen Gleichgewichtsabstand von 1.608 für den (1) 1 G g -Zustand von N 2 voraus, der 294.3 kcal mol À1 über dem X 1 S g + -Grundzustand liegt. [19] Die RI-BP86/def2-TZVPP-Berechnungen von N 2 (1) 1 G g ergeben einen N-N-Abstand von 1.661 und eine Anregungsenergie von 328.6 kcal mol À1 . Angesichts der Näherungen der DFT-Methode ist dies eine bemerkenswert gute Übereinstimmung mit dem Ab-initio- Die Rechnungen lassen demnach darauf schließen, dass die sehr starke Ph 3 P!N 2 ( Die oben genannten Ergebnisse deuten an, dass die Donor-Akzeptor-Wechselwirkungen [20] in Hauptgruppenverbindungen der Atome der ersten Achterperiode mçglicher- [21] dass Carbodiphosphorane C(PR 3 ) 2 , die bereits 1961 [22] synthetisiert wurden, Beispiele für die Verbindungsklasse der Carbone CL 2 sind.…”