138 research outputs found
Naturally-meaningful and efficient descriptors: machine learning of material properties based on robust one-shot ab initio descriptors
Establishing a data-driven pipeline for the discovery of novel materials
requires the engineering of material features that can be feasibly calculated
and can be applied to predict a material's target properties. Here we propose a
new class of descriptors for describing crystal structures, which we term
Robust One-Shot Ab initio (ROSA) descriptors. ROSA is computationally cheap and
is shown to accurately predict a range of material properties. These simple and
intuitive class of descriptors are generated from the energetics of a material
at a low level of theory using an incomplete ab initio calculation. We
demonstrate how the incorporation of ROSA descriptors in ML-based property
prediction leads to accurate predictions over a wide range of crystals,
amorphized crystals, metal-organic frameworks and molecules. We believe that
the low computational cost and ease of use of these descriptors will
significantly improve ML-based predictions.Comment: 13 pages, accepted in Journal of Cheminformatic
Correlating the Energetics and Atomic Motions of the Metal-Insulator Transition of M1 Vanadium Dioxide
Materials that undergo reversible metal-insulator transitions are obvious
candidates for new generations of devices. For such potential to be realised,
the underlying microscopic mechanisms of such transitions must be fully
determined. In this work we probe the correlation between the energy landscape
and electronic structure of the metal-insulator transition of vanadium dioxide
and the atomic motions occurring using first principles calculations and high
resolution X-ray diffraction. Calculations find an energy barrier between the
high and low temperature phases corresponding to contraction followed by
expansion of the distances between vanadium atoms on neighbouring sub-lattices.
X-ray diffraction reveals anisotropic strain broadening in the low temperature
structure's crystal planes, however only for those with spacings affected by
this compression/expansion. GW calculations reveal that traversing this barrier
destabilises the bonding/anti-bonding splitting of the low temperature phase.
This precise atomic description of the origin of the energy barrier separating
the two structures will facilitate more precise control over the transition
characteristics for new applications and devices.Comment: 11 Pages, 8 Figure
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