Which density functional is close to CCSD accuracy to describe geometry and interaction energy of small noncovalent dimers? A benchmark study using Gaussian09

Abstract

A benchmark study on all possible density functional theory (DFT) methods in Gaussian09 is done to locate functionals that agree well with CCSD/aug-cc-pVTZ geometry and Ave-CCSD(T)/(Q-T) interaction energy (Eint) for small non-covalently interacting molecular dimers in "dispersion-dominated" (class 1), "dipole-induced dipole" (class 2), and "dipole-dipole" (class 3) classes. A DFT method is recommended acceptable if the geometry showed close agreement to CCSD result (RMSD < 0.045) and Eint was within 80-120% accuracy. Among 382 tested functionals, 1-46% gave good geometry, 13-44% gave good Eint , while 1-33% satisfied geometry and energy criteria. Further screening to locate the best performing functionals for all the three classes was made by counting the acceptable values of energy and geometry given by each functionals. The meta-generalized gradient approximation (GGA) functional M06L was the best performer with total 14 hits; seven acceptable energies and seven acceptable geometries. This was the only functional "recommended" for at least two dimers in each class. The functionals M05, B2PLYPD, B971, mPW2PLYPD, PBEB95, and CAM-B3LYP gave 11 hits while PBEhB95, PW91B95, Wb97x, BRxVP86, BRxP86, HSE2PBE, HSEh1PBE, PBE1PBE, PBEh1PBE, and PW91TPSS gave 10 hits. Among these, M05, B971, mPW2PLYPD, Wb97x, and PW91TPSS were among the "recommended" list of at least one dimer from each class. Long-range correction (LC) of Hirao and coworkers to exchange-correlation functionals showed massive improvement in geometry and Eint . The best performing LC-functionals were LC-G96KCIS and LC-PKZBPKZB. Our results predict that M06L is the most trustworthy DFT method in Gaussian09 to study small non-covalently interacting systems.

Charge Delocalization in Oligomers of Poly(2,5-bis(3-alkylthiophene-2-yl)thieno[3,2-b]thiophene) (PBTTT)

“…A coupled cluster approach using both single and double substitutions from the Hartree-Fock determinant (CCSD) [19][20][21][22] is often used as a benchmark. 23 Here, we choose the geometry of BTTT1 optimized at the CCSD/6-31G* level as a reference in order to compare the accuracy of the TRS-DFT functionals; for the sake of comparison, we also include results with B3LYP. 24,25 In addition, the BTTT1 geometry is also optimized at the B3LYP/6-31+G(d,p) levels to better assess basis set vs. functional effects.…”

A DFT study on the thermal cracking of JP-10

“…The reliability of the chosen method has already been demonstrated by various work [32][33][34][35][36][37]. The 6-31+g(d) basis set was used for the C, O, and H atoms.…”

Revisiting the Stereochemistry of Propylene Isotactic Polymerization Reaction Mechanism on C2 Symmetric [SiH2(Ind)2ZrCH3]+ and [SiH2(Ind)2ZrCH3]+[CH3B(C6F5)3]−

“…Moreover, the M06 level was successfully used for dispersion correction and long-range correction in organic molecules and organometallics complexes. 54,55 Atoms-in-molecules (AIM) analysis was conducted on the intermediate catalysts and ion pairs of first insertion products using AIMALL software. 56 The wave function was created from the Gaussian 09 for calculating bond critical points between non-bonded atoms.…”