A critical analysis of electronic density functionals for structural, energetic, dynamic, and magnetic properties of hydrogen fluoride clusters

Basis set effects on the energy and hardness profiles of the hydrogen fluoride dimer

“…In contrast, the 3-21G, 6-31G, and 6-311G(d, p) PESs only present one spurious minimum at the C 2h cyclic structure, showing the well-known importance of the diffuse functions to accurately describe the hydrogen-bonded complex of the HF dimer. 4,8 Finally, the STO-3G PES predicts four stationary points instead of two. In contrast to the 3-21G and 6-31G basis sets, the STO-3G basis set characterizes the minimum at 5°.…”

“…This is particularly true in the case of chemical reactions, where the number and/or nature of stationary points (minima or transition states) may change with the basis set and/or the method of calculation. [3][4][5][6][7][8] In these pathological systems, high level ab initio methods (not always computationally affordable) are required to be certain of the correctness of the calculated PES.…”

“…However, DFT methods also show pathological behaviors, the hydrogen fluoride (HF) dimer being a classical example in the literature. [4][5][6][7][8] Both experiment and high level calculations indicate that the HF dimer has a planar (C s ) equilibrium structure (see figure 1). One HF molecule forms a nearly linear hydrogen bond to the other.…”

“…One HF molecule forms a nearly linear hydrogen bond to the other. 4,5 Moreover, the PES of HF dimer also contains a transition state with C 2h cyclic structure, that connects the two possible C s minima.…”

Toward elimination of discrepancies between theory and experiment: The rate constant of the atmospheric conversion of SO 3 to H 2 SO 4

“…single, double, and perturbational triple excitation energies at geometries found by application of second-order Møller Plesset perturbation theory (CCSD(T)͞aug-cc-pVDZ͞͞MP2͞aug-ccpVDZ) (55-57) served as verification of the generally high performance of hybrid density functional theory B3LYP for hydrogen-bonded clusters (58)(59)(60)(61).…”