- Title
- Density functional tight binding-based free energy simulations in the DFTB plus program
- Creator
- Mitchell, Izaac; Aradi, Balint; Page, Alister J.
- Relation
- ARC.LE170100032 http://purl.org/au-research/grants/arc/FL170100032
- Relation
- Journal of Computational Chemistry Vol. 39, Issue 29, p. 2452-2458
- Publisher Link
- http://dx.doi.org/10.1002/jcc.25583
- Publisher
- Wiley-Blackwell
- Resource Type
- journal article
- Date
- 2018
- Description
- The timescale problem—in which high barriers on the free energy surface trap molecular dynamics simulations in local energy wells—is a key limitation of current reactive MD simulations based on the density functional tight binding (DFTB) potential. Here, we report a new interface between the DFTB+ software package and the PLUMED library for performing DFTB-based free energy calculations. We demonstrate the performance of this interface for 3 archetypal rare-event chemical reactions, (i) intramolecular proton transfer in malonaldehyde, (ii) bowl inversion in corannulene, and (iii) oxygen diffusion on graphene. Using third-order DFTB in conjunction with metadynamics (with/without multiple walkers) and well-tempered metadynamics, we report here free energies of activation (ΔG‡) of 13.1 ± 0.4, 48.2 ± 1.7, and 52.0 ± 6.2 kJ mol−1, respectively, for these processes. In each case, our DFTB free energy barriers and local minima compare favorably with previous literature results, demonstrating the utility of the DFTB+ - PLUMED interface.
- Subject
- corannulene; density functional tight binding; graphene oxide; metadynamics; proton transfer
- Identifier
- http://hdl.handle.net/1959.13/1447475
- Identifier
- uon:43156
- Identifier
- ISSN:0192-8651
- Language
- eng
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