We introduce QM7-X, a comprehensive dataset of 42 physicochemical properties
for $\approx$ 4.2 M equilibrium and non-equilibrium structures of small organic
molecules with up to seven non-hydrogen (C, N, O, S, Cl) atoms. To span this
fundamentally important region of chemical compound space (CCS), QM7-X includes
an exhaustive sampling of (meta-)stable equilibrium structures - comprised of
constitutional/structural isomers and stereoisomers, e.g., enantiomers and
diastereomers (including cis-/trans- and conformational isomers) - as well as
100 non-equilibrium structural variations thereof to reach a total of $\approx$
4.2 M molecular structures. Computed at the tightly converged
quantum-mechanical PBE0+MBD level of theory, QM7-X contains global (molecular)
and local (atom-in-a-molecule) properties ranging from ground state quantities
(such as atomization energies and dipole moments) to response quantities (such
as polarizability tensors and dispersion coefficients). By providing a
systematic, extensive, and tightly-converged dataset of quantum-mechanically
computed physicochemical properties, we expect that QM7-X will play a critical
role in the development of next-generation machine-learning based models for
exploring greater swaths of CCS and performing in silico design of molecules
with targeted properties.

QM7-X 是一个全面的数据集，其中包含大量的有机分子的 42 个理化特性，这些分子具有高达七个非氢（C，N，O，S，Cl）原子，并为量子力学 PBE0 + MBD 级别的计算提供了定量收敛的结果，这一数据集对探索化合物空间并针对性地设计具有特定属性的分子的机器学习模型的发展将起到至关重要的作用。