Molecular NMR shieldings, J-couplings, and magnetizabilities from numeric atom-centered orbital based density-functional calculations

TL;DR

This paper presents a scalable, accurate method for calculating NMR shieldings, J-couplings, and magnetizabilities using numeric atom-centered orbital basis sets within density functional theory, outperforming traditional Gaussian basis sets in convergence speed.

Contribution

The authors introduce a new implementation for NMR property calculations using NAO basis sets, including a novel NAO-J-n basis set optimized for J-couplings, demonstrating improved convergence and scalability.

Findings

NAO basis sets reach basis set limit faster than Gaussian basis sets.

NAO-VCC-nZ basis sets have similar accuracy to Jensen's pcS-n basis sets for shieldings.

The new NAO-J-n basis sets show convergence similar to pcJ-n basis sets for J-couplings.

Abstract

We describe an accurate and scalable implementation for the computation of molecular nuclear magnetic resonance shieldings, J-couplings, and magnetizabilities within nonrelativistic semilocal density functional theory, based on numeric atom-centered orbital (NAO) basis sets. We compare the convergence to the basis set limit for two established types of NAO basis sets, called NAO-VCC-nZ and FHI-aims-09, to several established Gaussian-type basis sets. The basis set limit is reached faster for the NAO basis sets than for standard correlation consistent Gaussian-type basis sets (cc-pVnZ, aug-cc-pVnZ, cc-pCVnZ, aug-cc-pCVnZ). For shieldings, the convergence properties and accuracy of the NAO-VCC-nZ basis sets are similar to Jensen's polarization consistent (pc) basis sets optimized for shieldings (pcS-n). For J-couplings, we develop a new type of NAO basis set (NAO-J-n) by augmenting the NAO-VCC-nZ basis sets with tight s-functions from Jensen's pcJ-n basis sets, which are optimized for J-couplings. We find the convergence of the NAO-J-n to be similar to the pcJ-n basis sets. Large scale applicability of the implementation is demonstrated for shieldings and J-couplings in a system of over 1,000 atoms.