Ro-vibrational spectra of the simplest deuterated criegee intermediate CD₂OO^†

Criegee intermediates are of significance in the atmospheric chemistry. In this work, the ro-vibrational spectra of the simplest deuterated Criegee intermediate, CD₂OO, were studied by a vibrational self-consistent field/virtual configuration interaction (VSCF/VCI) method based on a nine-dimensional accurate potential energy surface and dipole surface for its ground electronic state. The calculated fundamental vibrational frequencies and rotational constants are in excellent agreement with the available experimental results. These data are useful for further spectroscopic studies of CD₂OO. Especially, the rotational constants for excited vibrational levels are essential for experimental spectral assignments. However, the infrared intensities from different resources, including the current computation, the experiment, and previous calculations at the NEVPT2 and B3LYP levels, deviate significantly.