A computational framework for evaluating molecular dynamics potential parameters employing quantum mechanics

Abstract

Molecular dynamics (MD) and Quantum Mechanics (QM) calculations can be used to characterize novel materials and phenomena that experimental methods cannot capture. While QM provides accurate results, it is at...

Computational Framework Combining Quantum Mechanics, Molecular Dynamics, and Deep Neural Networks to Evaluate the Intrinsic Properties of Materials

“…The results for ethanol and octane molecular systems, although not as accurate, are still reasonable. The MD simulation results for predicting melting points for the same molecules under the same condition but using classic MD force fields extracted from reference are shown in Figure S2 in the Supporting Information. It is important to note that except for the EC molecule, the pristine framework is unable to determine the melting points of these molecules.…”

“…The key to an accurate MD simulation is the use of appropriate and accurate potential parameters. In a recent study, we presented a suite of algorithms for evaluating the potential parameters for the nonbonded, bonded, angle, dihedral, and improper interactions . However, due to the complexity of nonbonded interactions and the mentioned restriction of conventional mathematical methods, we introduced several simplifications that impacted the accuracy of the results.…”

“…For instance, bonded interactions between two atoms in a bond can be obtained by the harmonic potential equation U bonded ( l ) = A ( l – l 0 ) 2 , where A and l 0 , the constant coefficients, are called the potential parameters and l is the bond length. With such formulations, the computational costs are significantly minimized, and the MD simulations can study systems with ∼10 6 particles that are more than 1000 times larger than the size of the systems that can be investigated by QM simulations and for a much larger timescale than what is possible with the QM simulations. − However, MD simulations are dependent on the potential equations/parameters that are often obtained from experimental studies.…”

“…Recent works of Neumann, Berryman et al, and Lanjan et al focus on the development of computational frameworks that couple the QM and MD calculations for evaluating potential parameters for the tailor-made and/or classical force fields as an alternative to experimental techniques. This approach selects a tiny sample of the main system and evaluates its energy as a function of a structural change (e.g., bond length) while other effective parameters are maintained at their minimum energy level.…”

“…QM simulations can only be employed with small systems with a few atoms. MD simulations cannot be done without the experimental data on the potential parameters. , To overcome this bottleneck in computational nano-based techniques, a combination of QM and MD simulations are often employed. ,− …”