Skip to Main content Skip to Navigation
Journal articles

Free Energy Profiles of Proton Transfer Reactions: Density Functional Benchmark from Biased Ab Initio Dynamics

Abstract : By coupling an enhanced sampling algorithm with an orbital-localized variant of Car–Parrinello molecular dynamics, the so-called atomic centered density matrix propagation model, we reconstruct the free energy profiles along reaction pathways using different density functional approximations (DFAs) ranging from locals to hybrids. In particular, we compare the computed free energy barrier height of proton transfer (PT) reactions to those obtained by a more traditional static approach, based on the intrinsic reaction coordinate (IRC), for two case systems, namely malonaldehyde and formic acid dimer. The obtained results show that both the IRC profiles and the potentials of mean force, derived from biased dynamic trajectories, are very sensitive to the density functional approximation applied. More precisely, we observe that, with the notable exception of M06-L, local density functionals always strongly underestimate the reaction barrier heights. More generally, we find that also the shape of the free energy profile is very sensitive to the density functional choice, thus highlighting the effect, often neglected, that the choice of DFA has also in the case of dynamics simulations.
Document type :
Journal articles
Complete list of metadata

https://hal-univ-paris.archives-ouvertes.fr/hal-03668915
Contributor : Equipe HAL Université Paris Cité Connect in order to contact the contributor
Submitted on : Monday, May 16, 2022 - 11:19:12 AM
Last modification on : Wednesday, May 18, 2022 - 3:13:24 AM

Identifiers

Collections

Citation

Eric Brémond, Marika Savarese, Nadia Rega, Ilaria Ciofini, Carlo Adamo. Free Energy Profiles of Proton Transfer Reactions: Density Functional Benchmark from Biased Ab Initio Dynamics. Journal of Chemical Theory and Computation, American Chemical Society, 2022, 18 (3), pp.1501-1511. ⟨10.1021/acs.jctc.1c01002⟩. ⟨hal-03668915⟩

Share

Metrics

Record views

4