The Jahn-Teller and Related Effects in the Silver Trimer, Part I: The Ab Initio Calculation of Spectroscopically Observable Parameters

Extensive ab initio calculations were performed for the X̃ 2E′ and à 2E′′ states of Ag3, using a newly constructed basis set for Ag. An important goal of these calculations is to guide the analysis of the experimentally observed à 2E′′-X̃ 2E′ electronic spectrum. Vibrational frequencies of Ag3 for both the X̃ and à state are reported. Spectroscopically obtainable parameters describing the Jahn-Teller effect are calculated for the X̃ and à states. The magnitude of the spin-orbit effects for this relativistic system was also calculated for the X̃ 2E′ and à 2E′′ states. Using all this information, the X̃ − à electronic spectrum is predicted for Ag3. Additionally, the geometries and symmetries of the global minima and saddle points as well as the barrier to pseudorotation around the moat of the potential energy surface are determined for both states.