Effect of vibration and rotation on the internuclear distance

Thermal Effects and Vibrational Corrections to Transition Metal NMR Chemical Shifts

“…In principle, the more approximate perturbational approach that we have employed for the zero-point corrections can be extended to evaluate effective geometries and averaged properties at thermal equilibrium for a given temperature. [73,74] To our knowledge, however, systematic tests and benchmarks for this method have not yet reported. [75] Clearly, further research efforts in this direction are warranted.…”

Rovibrationally Averaged Nuclear Shielding Constants in OCS

“…͗Q k ͘ T and ͗Q k 2 ͘ T are obtained using the known approximation of Toyama et al (35), as implemented in the AVIBR program (36). ͗Q k 2 ͘ T are computed from the zeroth order wavefunctions of the harmonic oscillators, i.e., over the harmonic vibrations of the molecule:…”

Effects of vibrational anharmonicity on19F nuclear resonance in SF6

“…For SF~-type molecules : Just as in equations (14) and (15), these terms are expressible in terms of oJ i and the L matrix elements in the transformation between the symmetry coordinates and normal coordinates. Bartell Temperature dependence of mean SI" bond length in SF6, calculated by the method of Toyama et al [7] (see text, equations (4)-(6)), compared with that calculated by the approximate method of Bartell [9]. The contributions (Bartell method).from Morse anharmonicity, non-bonded repulsion, bending centrifugal stretch, rotational centrifugal stretch and minor-cross terms are also indicated.…”