摘要

Highly correlated ab initio wave functions within the UCCSD(T)-F12 approach have been used to map portions of the potential energy surfaces and to study the stability of the first excited triplet states of the NCS-/CNS- and NCO-/CNO- anions. These a(3)pi states for linear geometries, or their (3)A ' and (3)A '' bent components, correlate with the lowest dissociation asymptote of NCX- (X = S and O) along the NC-X coordinates. The X-1 sigma(+) linear ground states of these anions are known to be stable with respect to dissociation to the X-2 pi ground state of the corresponding neutral molecule with a rather large electron affinity. The a(3)pi state of the NCS- anion is positioned below the X state of the neutral at long NC-S distances and its minimum of energy is found for bent geometries. The stability of its two components in bent geometries has been investigated, and it is found that some anionic forms are stable with respect to the X state of the neutral. The linear CNS- and CNO- isomers present a minimum only at long CN-X distances, located below the minimum of their corresponding neutral CNX ground states.

  • 出版日期2015-7-18