Nb–Nb Interactions Define the Charge Density Wave Structure of 2H-NbSe₂

Abstract

2H-NbSe₂ is a canonical Charge-Density-Wave (CDW) layered material the structural details of which remained elusive. We report the detailed structure of 2H-NbSe₂ below the CDW transition using a (3 + 2)-dimensional crystallographic approach on single crystal X-ray diffraction data collected at 15 K. Intensities of main reflections as well as CDW satellites of first order were measured. Quantitative information about the magnitude of the structural distortions and clustering of Nb atoms were extracted from the refined model. The Nb–Nb distances were found to distort between 3.4102(8) and 3.4928(8) Å in the CDW phase from the average undistorted distance of 3.4583(4) Å