
%0 Journal Article
%A Hughes, Jason M. 
%A von, Ellak I. 
%A Nagy-Felsobuki, 
%T Ab Initio Investigations of the Electronic Structure of HeNH <emph type="7">+</emph> and HeNH <emph type="7">2+</emph>
%J Australian Journal of Physics
%D 1998/02/10
%V 51
%N 1
%P 57-66
%K 
%R https://doi.org/10.1071/P97041
%U https://www.publish.csiro.au/paper/P97041 
%X Electronic structures of HeNH+ and HeNH2+ were investigated using the all-electron coupled cluster single, double and triple excitation (CCSD(T)&lowbar;AE) method coupled with an augmented correlation-consistent polarised core valence triple zeta basis set (aug-cc-pCVTZ). For HeNH+ and HeNH2+, the CCSD(T)&lowbar;AE/aug-cc-pCVTZ model yielded cations of Cs symmetry with 2 A&Prime; and 1 A&#8242; ground electronic states possessing optimised geometrical parameters &#123;rN-H; rN-He; &#952;H-N-He&#125; of &#123;1&#183;064 &#197;, 1&#183;517 &#197;, 88&#183;5&#176;&#125; and &#123;1&#183;192 &#197;, 1&#183;309 &#197;, 96&#183;2&#176;&#125; respectively. Of all the linear isomeric forms possible for these two cations, the only converged minimum energy structures were for the 4&#931;- states of HeHN+ and HeNH+ yielding optimised structural parameters of &#123;1&#183;093 &#197;, 2&#183;403 &#197;, 180&#183;0&#176;&#125; and &#123;1&#183;117 &#197;, 1&#183;364 &#197;, 180&#183;0&#176;&#125; respectively. These two linear structures were calculated to be 9&#183;6 and 18&#183;6 kJ mol-1 respectively above the Cs structure. The calculated harmonic frequencies were real for all these states and their magnitudes were sensitive to the incorporation of electron correlation. 
