Most small dianions known in the solid state and solutions cannot exist as isolated entities and decay in the gas phase by electron autodetachment. These dianions show rare-gas-like closed-shell electronic ground states and represent a new type of metastable system. Here we study the prototype closed-shell resonance C2^2− in the framework of the complex absorbing potential method. We investigate in detail a number of unsettled methodological issues. In particular, there is no “natural” choice of orbital set for closed-shell metastable states and we study several orbital sets as well as other basis set and correlation effects on resonance energy and width. Closed-shell resonances typically show several open decay channels and we compute partial widths for the three open channels of C2^2−. Finally, we study the complex potential energy curve and compare our bond lengths and vibrational frequencies with geometrical parameters which have been obtained ignoring the metastable character of C2^2−.
Ab initio calculation of energies and lifetimes of metastable dianions: The C2— resonance
TARANTELLI, Francesco;
2000
Abstract
Most small dianions known in the solid state and solutions cannot exist as isolated entities and decay in the gas phase by electron autodetachment. These dianions show rare-gas-like closed-shell electronic ground states and represent a new type of metastable system. Here we study the prototype closed-shell resonance C2^2− in the framework of the complex absorbing potential method. We investigate in detail a number of unsettled methodological issues. In particular, there is no “natural” choice of orbital set for closed-shell metastable states and we study several orbital sets as well as other basis set and correlation effects on resonance energy and width. Closed-shell resonances typically show several open decay channels and we compute partial widths for the three open channels of C2^2−. Finally, we study the complex potential energy curve and compare our bond lengths and vibrational frequencies with geometrical parameters which have been obtained ignoring the metastable character of C2^2−.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
