atomic polar tensor

units: $\pu{C}$, $\pu{D Å-1}$
initialism: APT
https://doi.org/10.1351/goldbook.08572
3 × 3 tensor that gives the change in the components of the molecular dipole moment when the atom is displaced in three-dimensional space.
Notes:
  1. The rows correspond to different components of the dipole moment and the columns to \(x\), \(y\) and \(z\) displacements.
  2. APTs have been widely used in the analysis of infrared absorption intensities.
  3. SI unit: \(\pu{C}\). Common unit: \(\pu{D Å-1 \approx 3.33564E-30 C}\).
Source:
PAC, 2021, 93, 647. 'Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)' on page 739 (https://doi.org/10.1515/pac-2019-0203)