Coarse-grained molecular dynamics (MD) simulation is
a promising
alternative to all-atom MD simulation for the fast calculation of
system properties, which is imperative in designing materials with
a specific target property. There have been several coarse-graining
strategies developed over the past few years that provide accurate
structural properties of the system. However, these coarse-grained
models share a major drawback in that they introduce an artificial
acceleration in molecular mobility. In this paper, we report a data-driven
approach to generate coarse-grained models that preserve the all-atom
molecular mobility. We designed a machine learning model in the form
of an artificial neural network, which directly predicts the simulation-ready
mobility-preserving coarse-grained potential as an output given the
all-atom force field (FF) parameters as inputs. As a proof of principle,
we took 2,3,4-trimethylpentane as a model system and described the
development of machine learning models in detail. We quantify the
artificial acceleration in molecular mobility by defining the acceleration
factor as the ratio of the coarse-grained and the all-atom diffusion
coefficient. The predicted coarse-grained potential generated by the
best machine learning model can bring down the acceleration factor
to a value of ∼2, which could be otherwise as large as 7 for
a typical value of 3 × 10–9 m2 s–1 for the all-atom diffusion coefficient. We believe
our method will be of interest in the community as a route to generating
coarse-grained potentials with accurate dynamics.