Pure and Hybrid SCAN, rSCAN, and r2SCAN: Which One Is Preferred in KS- and HF-DFT Calculations, and How Does D4 Dispersion Correction Affect This Ranking?

Abstract

Using the large and chemically diverse GMTKN55 dataset, we have tested the performance of pure and hybrid KS-DFT and HF-DFT functionals constructed from three variants of the SCAN meta-GGA exchange-correlation functional: original SCAN, rSCAN, and r2SCAN. Without any dispersion correction involved, HF-SCANn outperforms the two other HF-DFT functionals. In contrast, among the self-consistent variants, SCANn and r2SCANn offer essentially the same performance at lower percentages of HF-exchange, while at higher percentages, SCANn marginally outperforms r2SCANn and rSCANn. However, with D4 dispersion correction included, all three HF-DFT-D4 variants perform similarly, and among the self-consistent counterparts, r2SCANn-D4 outperforms the other two variants across the board. In view of the much milder grid dependence of r2SCAN vs. SCAN, r2SCAN is to be preferred across the board, also in HF-DFT and hybrid KS-DFT contexts.

Slater transition methods for core-level electron binding energies

“…85 where a numerical orbital representation was used, but the differences do not concern us given the SCAN functional's well known sensitivity to the quality of the numerical integration grid. [87][88][89] As applied to ethyl trifluoroacetate, the original STM approach exhibits errors of 1-2 eV for some of the functionals tested. However, shifted-STM values (using β parameters optimized for the CORE65 test set) exhibit errors that are smaller than those obtained using GW methods.…”

Extending density functional theory with near chemical accuracy beyond pure water

“…To illustrate what can happen when these principles are not applied, we show results from ref. 64 . This is a version of HF-r 2 SCAN-D4, but where all reactions in GMTKN55 were used, and the WTMAD-2 40 was used as the cost function instead.…”

In Search of Preferential Macrocyclic Hosts for Sulfur Mustard Sensing and Recognition: A Computational Investigation through the New Composite Method r2SCAN-3c of the Key Factors Influencing the Host-Guest Interactions

“…Full geometry optimization and energy calculations were performed using the recently developed meta-generalized-gradient approximation (mGGA) composite method r 2 SCAN-3c [ 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 ] combined with a modified version of the def2-TZVP basis set [ 58 ] denoted def2-mTZVPP [ 49 ]. A geometrical counterpoise correction (gCP) for the intra- and inter-molecular basis set superposition error was employed [ 59 ], as well as the Grimme dispersion term based on tight-binding partial charges (D4) [ 60 , 61 , 62 ] that was applied to account for the dispersion correction.…”