The past few years have witnessed significant advances
in developing
machine learning methods for molecular energetics predictions, including
calculated electronic energies with high-level quantum mechanical
methods and experimental properties, such as solvation free energy
and logP. Typically, task-specific machine learning models are developed
for distinct prediction tasks. In this work, we present a multitask
deep ensemble model, sPhysNet-MT-ens5, which can simultaneously and
accurately predict electronic energies of molecules in gas, water,
and octanol phases, as well as transfer free energies at both calculated
and experimental levels. On the calculated data set Frag20-solv-678k,
which is developed in this work and contains 678,916 molecular conformations,
up to 20 heavy atoms, and their properties calculated at B3LYP/6-31G*
level of theory with continuum solvent models, sPhysNet-MT-ens5 predicts
density functional theory (DFT)-level electronic energies directly
from force field-optimized geometry within chemical accuracy. On the
experimental data sets, sPhysNet-MT-ens5 achieves state-of-the-art
performances, which predict both experimental hydration free energy
with a RMSE of 0.620 kcal/mol on the FreeSolv data set and experimental
logP with a RMSE of 0.393 on the PHYSPROP data set. Furthermore, sPhysNet-MT-ens5
also provides a reasonable estimation of model uncertainty which shows
correlations with prediction error. Finally, by analyzing the atomic
contributions of its predictions, we find that the developed deep
learning model is aware of the chemical environment of each atom by
assigning reasonable atomic contributions consistent with our chemical
knowledge.