Accurate predictions of chemical shifts with the rSCAN and r2SCAN mGGA exchange–correlation functionals

Abstract

We benchmark the rSCAN and r²SCAN exchange–correlation functionals by comparing the Nuclear Magnetic Resonance (NMR) magnetic shieldings predicted by Density Functional Theory (DFT) to experimentally observed chemical shifts of halide and oxide inorganic compounds. Significant improvement in accuracy is achieved compared to the Generalised Gradient Approximation (GGA) at a marginally higher computational cost. When using rSCAN or r²SCAN, the correlation coefficient between computationally predicted and experimental values approaches the theoretically expected value of −1 while reducing the deviation, allowing more accurate and reliable spectrum assignments of complex compounds in experimental investigations.