Hydrogen-bonding in glycine and malonaldehyde: Performance of the Lap1 correlation functional

摘要: The conformational equilibrium of gaseous glycine presents a severe challenge to quantum chemistry and, in particular, density functional theory (DFT), due the presence internal hydrogen bonds. We present new DFT results for structure and energetics malonaldehyde, using recently developed nonlocal exchange-correlation functionals BLap1 PLap1. A comparative analysis is made with generalized-gradient-approximation (GGA) schemes Becke–Perdew (BP86) Becke–Lee–Yang–Parr (BLYP), hybrid Hartree–Fock (HF)-DFT methods B3PW91 B3LYP, post-HF methods, available experimental data. Our BLap1/TZVP PLap1/TZVP values energy margin between two lowest conformers (0.84 1.05 kcal/mol, respectively) are within error bars (1.0±0.5 kcal/mol). MP2 underestimates this difference by about 0.5 BLYP off 0.9 kcal/mol. optimized geometry malo...