title: Temperature Dependence of NMR Parameters Calculated from Path Integral Molecular Dynamics Simulations.
abstract: The influence of temperature on NMR chemical shifts and quadrupolar couplings in model molecular organic solids is explored using path integral molecular dynamics (PIMD) and density functional theory (DFT) calculations of shielding and electric field gradient (EFG) tensors. An approach based on convoluting calculated shielding or EFG tensor components with probability distributions of selected bond distances and valence angles obtained from DFT-PIMD simulations at several temperatures is used to calculate the temperature effects. The probability distributions obtained from the quantum PIMD simulations, which includes nuclear quantum effects, are significantly broader and less temperature dependent than those obtained with conventional DFT molecular dynamics or with 1D scans through the potential energy surface. Predicted NMR observables for the model systems were in excellent agreement with experimental data.
authors: Institute of Organic Chemistry and Biochemistry , Flemingovo nám. 2, 16610 Prague, Czech Republic.
authors: Martin
authors: M
authors: Dračínský
authors: Institute of Organic Chemistry and Biochemistry , Flemingovo nám. 2, 16610 Prague, Czech Republic.
authors: Petr
authors: P
authors: Bouř
authors: Department of Chemistry, Durham University , South Road, DH1 3LE Durham, United Kingdom.
authors: Paul
authors: P
authors: Hodgkinson