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 T3/2 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 2D metal.