P. Piecuch et al., DIPOLE-MOMENT AND POLARIZABILITY FUNCTIONS OF AMMONIA - A LINEAR-RESPONSE COUPLED-CLUSTER STUDY, Polish Journal of Chemistry, 72(7), 1998, pp. 1635-1656
The recently developed orthogonally spin-adapted linear-response coupl
ed-cluster theory with singly and doubly excited clusters (LRCCSD) has
been employed to calculate the dipole moment and parallel polarizabil
ity functions of ammonia over a wide range of values of the inversiona
l and symmetric stretch coordinates. Using the eigenstates of the expe
rimentally derived nonrigid invertor Hamiltonian of ammonia and the LR
CCSD property functions, the transition dipole moments between several
low-lying inversional states and the rovibrationally averaged paralle
l polarizabilities for several values of the inversional quantum numbe
r have been evaluated. The calculated transition dipole moments and ro
vibrationally averaged polarizabilities have been found to be in excel
lent agreement wi th the available experimental and theoretical data,
indicating the suit ability of the nb initio LRCCSD theory for such ca
lculations. The LRCCSD transition dipole moments are far more accurate
than all previously obtained nb initio values.