IMPROVING ACCURACY OF COMPOSITE METHODS: A G4MP2 METHOD WITH G4-LIKE ACCURACY AND IMPLICATIONS FOR MACHINE LEARNING

(top) Comparison of G4MP2 and G4MP2A methods with the G4 method, the highest level of this series of methods, which shows that the addition of the atom specific correction (G4MP2A) significantly improves accuracy (MAD = mean absolute deviation). (bottom) Breakdown of machine learning results based on G4MP2A as a function of molecule size (number of non-hydrogen atoms).

Scientific Achievement

This work introduces a new method to improve quantum chemical predictions of energies of large organic molecules that can also be used in combination with machine learning to predict molecular energies at a much lower cost of computer time.

Significance and Impact

This study significantly enhances the accuracy by which quantum chemical methods combined with machine learning methods can be used to screen energy properties of molecules, such as reaction energies and ionization potentials. The ability to rapidly make such predictions with greater accuracy will greatly expand computational capabilities for exploration of potential electrolyte molecules.

Research Details

  • Investigated the cause of the increase in error compared to experiment in the quantum chemical method G4MP2 when applied to larger organic molecules with 10 or more non-hydrogen atoms.
  • In order to address this problem we added an atom-specific correction to the method, which is dependent on the type of atom, not on the bond type. This makes the method significantly more accurate with no additional computational time.
  • The new method, G4MP2A, has been used in a Δ-learning ML method to predict molecular energies with improved accuracy and reduced computational cost.

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doi.org/10.1021/acs.jpca.2c01327

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