5.3.1 Suggested Density Functionals

Q-Chem contains over 150 exchange-correlation functionals, not counting those that can be straightforwardly appended with a dispersion correction (such as B3LYP-D3). Therefore, we suggest a few functionals from the second through fourth rungs of Jacob’s Ladder in order to guide functional selection. Most of these suggestions come from a benchmark of over 200 density functionals on a vast database of nearly 5000 data points, covering non-covalent interactions, isomerization energies, thermochemistry, and barrier heights. The single recommended method from each category is indicated in bold.

From the GGAs on Rung 2, we recommend:

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  B97-D3(BJ): METHOD B97-D3 and DFT_D D3_BJ

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  revPBE-D3(BJ): METHOD revPBE and DFT_D D3_BJ

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  BLYP-D3(BJ): METHOD BLYP and DFT_D D3_BJ

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  PBE: METHOD PBE

From the meta-GGAs on Rung 3, we recommend:

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  B97M-rV: METHOD B97M-rV

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  MS1-D3(0): METHOD MS1 and DFT_D D3_ZERO

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  MS2-D3(0): METHOD MS2 and DFT_D D3_ZERO

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  M06-L-D3(0): METHOD M06-L and DFT_D D3_ZERO

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  TPSS-D3(BJ): METHOD TPSS and DFT_D D3_BJ

From the hybrid GGAs on Rung 4, we recommend:

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  $\omega$B97X-V: METHOD wB97X-V

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  $\omega$B97X-D3: METHOD wB97X-D3

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  $\omega$B97X-D: METHOD wB97X-D

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  B3LYP-D3(BJ): METHOD B3LYP and DFT_D D3_BJ

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  revPBE0-D3(BJ): METHOD revPBE0 and DFT_D D3_BJ

From the hybrid meta-GGAs on Rung 4, we recommend:

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  $\omega$B97M-V: METHOD wB97M-V

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  $\omega$M05-D: METHOD wM05-D

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  M06-2X-D3(0): METHOD M06-2X and DFT_D D3_ZERO

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  TPSSh-D3(BJ): METHOD TPSSh and DFT_D D3_BJ

From the double-hybrid GGAs on Rung 5, we recommend:

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  $\omega$B97X-2(LP): METHOD wB97X-2(LP)

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  $\omega$B97X-2(TQZ): METHOD wB97X-2(TQZ)

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  DSD-PBEPBE-D3: METHOD DSD-PBEPBE-D3

From the double-hybrid mGGAs on Rung 5, we recommend:

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  $\omega$B97M-(2): METHOD wB97M-(2)

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  PTPSS-D3: METHOD PTPSS-D3