Density Functionals

MGCDB84 database

NCED - Non-covalent interactions (dimers) [easy] - 1744 data points

NCEC - Non-covalent interactions (clusters) [easy] - 243 data points

NCD - Non-covalent interactions (dimers) [difficult] - 91 data points

IE - Isomerization energies [easy] - 755 data points

ID - Isomerization energies [difficult] - 155 data points

TCE - Thermochemistry [easy] - 947 data points

TCD - Thermochemistry [difficult] - 258 data points

BH - Barrier Heights - 206 data points

The Main-Group Chemistry DataBase (MGCDB84) contains 84 datasets (4986 datapoints), requiring 5931 single point calculations per benchmarked functional. The database covers non-covalent interactions, isomerization energies, thermochemistry, and barrier heights. The entire database can be downloaded here.


Of the 84 datasets included in MGCDB84, 82 are categorized into eight datatypes: NCED, NCEC, NCD, IE, ID, TCE, TCD, and BH. The two datasets that are excluded from the datatype categorization are AE18 (absolute atomic energies) and RG10 (rare-gas dimer PECs). The first three datatypes (NCED, NCEC, and NCD) pertain to non-covalent interactions (NC), the next two datatypes (IE and ID) pertain to isomerization energies (I), the next two datatypes (TCE and TCD) pertain to thermochemistry (TC), and the last datatype pertains to barrier heights (BH). The datatype abbreviations begin with letters corresponding to one of the four main categories: NC, I, TC, or BH. Appending one of the four main categories with the letter ‘E’ indicates that the interactions within are considered to be ‘easy’ cases (not very sensitive to self-interaction error or strong correlation), while the letter ‘D’ indicates that the interactions are considered to be ‘difficult’. Finally, for the non-covalent interactions only, the presence of a fourth letter, either ‘D’ or ‘C’, indicates the presence of dimers or clusters, respectively.

The first table below contains benchmark data for 200+ density functionals. The values in columns six and onward are root-mean-square deviations (RMSD) in kcal/mol. The second column refers to the hybridization of the functional: Local (L), Global Hybrid (GH), or Range-Separated Hybrid (RSH). The third column refers to the ingredients in the functional: Local Spin-Density Approximation (LSDA), Generalized Gradient Approximation (GGA), or meta-Generalized Gradient Approximation (meta-GGA). The fourth column refers to the type of dispersion correction: no dispersion correction (None), Grimme's empirical damped atom-atom potentials (D2, D3(0), D3(BJ), D3M(BJ)), or the non-local correlation functional of Vydrov and Van Voorhis (VV10). Finally, the fifth column lists the fraction of exact exchange (or short-range exact exchange if the functional is an RSH).

The table below contains a summary of the 84 datasets that comprise MGCDB84. The datatypes are explained above. The fifth column contains the root-mean-squares of the dataset reaction energies. PEC stands for potential energy curve, SR stands for single-reference, MR stands for multi-reference, Bz stands for benzene, Me stands for methane, and Py stands for pyridine.