Vibrational energies and full analytic potential energy functions of PbI and InI from pure microwave data

Abstract

Pure rotational spectra of PbI and InI are interpreted to yield a full analytic potential energy function for each molecule. Rotational spectra for PbI have been retrieved from literature sources to perform the analysis. Rotational transition frequencies for excited vibrational states of InI (0 < v < 11) are measured during this work. Ignoring hyperfine splittings, B v and D v values are used to generate a set of "synthetic" pure R(0) transitions for each vibrational level. These are then fitted to an "Expanded Morse Oscillator" (EMO) potential using the direct-potential-fit program, DPOTFIT. The well-depth parameter, D e , is fixed at a literature value, while values of the equilibrium distance r e and EMO exponent-coefficient expansion (potential-shape) parameters are determined from the fits. Comparison with potential functions determined after including older mid-IR and visible electronic transition data shows that our analysis of the pure microwave data alone yields potential energy functions that accurately predict (to better than 1%) the overtone vibrational energies far beyond the range spanned by the levels for which the microwave data is available.

Parity-violating contributions to nuclear spin-rotation interactions and to NMR shielding constants in tetrahedral molecules

“…However, depending on We found the largest value of the NSR constant shift for the 209 Po nucleus in NPoHFI, on the order of 0.6 mHz. While the PV NSR constants presented in this paper do not reach the experimental sensitivity limit for NSR constants, which is on the order of 1-10 Hz [106,107], this work provides important insights into a possible direction in the experimental search for PV effects in chiral molecules. The same molecule was also found to have the largest value of the PV NMR shielding constants calculated in this work.…”