We introduce a method to evaluate the relative populations of different conformers of molecular species in solution, aiming at quantum mechanical accuracy, while keeping the computational cost at a nearly molecular-mechanics level. This goal is achieved by combining long classical molecular-dynamics simulations to sample the free-energy landscape of the system, advanced clustering techniques to identify the most relevant conformers, and thermodynamic perturbation theory to correct the resulting populations, using quantum-mechanical energies from density functional theory. A quantitative criterion for assessing the accuracy thus achieved is proposed. The resulting methodology is demonstrated in the specific case of cyanin (cyanidin-3-glucoside) in water solution.
|Titolo:||Sampling Molecular Conformers in Solution with Quantum Mechanical Accuracy at a Nearly Molecular-Mechanics Cost|
|Autori:||Rosa, Marta; Micciarelli, Marco; Laio, Alessandro; Baroni, Stefano|
|Data di pubblicazione:||2016|
|Digital Object Identifier (DOI):||10.1021/acs.jctc.6b00470|
|Appare nelle tipologie:||1.1 Journal article|