Properties of NoO and YbO.

Bond dissociation energies (BDEs) and spectroscopic parameters for the ground states of YbO and NoO were calculated at the Brueckner doubles (BD(T)) level and for NoO at the coupled cluster CCSD(T) level based on the closed-shell configurations Yb(4f)O(2p) and No(5f)O(2p). For YbO, the BD(T) BDE (3.93 eV) and vibrational frequency (686.

On the Cartesian Representation of the Molecular Polarizability Tensor Surface by Polynomial Fitting to Data.

We describe an approach to constructing an analytic Cartesian representation of the molecular dipole polarizability tensor surface in terms of polynomials in interatomic distances with a training set of data points obtained from a molecular dynamics (MD) simulation or by any other available means. The proposed formulation is based on a perturbation treatment of the unmodified point dipole polarizability model of Applequist [ 1972, 94, 2952] and is shown here to be, by construction (i) free of short-range or other singularities or discontinuities, (ii) symmetric and translationally invariant, and (iii) nonreliant on a body-fixed coordinate system. Permutational invariance of like nuclei is demonstrated to be readily applicable, making this approach useful for highly fluxional and reactive systems.