Electric field gradients in 2H–NbSe₂: ⁹³Nb NMR measurements and first-principles calculations

Accurate atomic scale structure is of importance for revealing the still mysterious electronic phase transitions in a famous 2D metal, 2H–NbSe₂. In this work, the electric field gradients (EFGs) of 2H–NbSe₂ at Nb sites in the normal state were investigated by ⁹³Nb nuclear magnetic resonance spectroscopy in combination with first-principles computations. The previous T ^3/2 and linear T models for describing the temperature dependent EFGs were tested and discussed according to our measured and theoretically computed EFG data in this two-dimensional metal. (paper)