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Record W7132926203

Robust Machine Learned Inter-atomic Potentials for Molecular Dynamics Simulations

2023· dissertation· W7132926203 on OpenAlex
Gurjot Singh Dhaliwal

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.

Bibliographic record

VenueTSpace · 2023
Typedissertation
Language
FieldMaterials Science
TopicMachine Learning in Materials Science
Canadian institutionsUniversity of Toronto
Fundersnot available
KeywordsSensitivity (control systems)Molecular dynamicsProperty (philosophy)Interatomic potentialReduction (mathematics)Bayesian probabilitySet (abstract data type)Uncertainty quantificationVariance (accounting)
DOInot available

Abstract

fetched live from OpenAlex

Molecular Dynamics (MD) simulations accelerated material discovery by performing property prediction at scales higher than Density functional theory (DFT). To make property prediction from MD simulations more robust, we propose an uncertainty quantification framework. The developed framework considers uncertainty in the parameters of the interatomic potential (IP) used to compute energy/forces between a set of atoms. We considered two distinct potentials namely AIREBO and Embedded atom method. The material of choice are graphene and aluminium. Sensitivity analysis was performed to understand the effects of IP parameter change on the final properties of interest. The sensitivity analysis showed that by varying the potential parameters as small as by 1%, the variance in the resulting mechanical properties was as high as 1e5. Basic properties such as elastic constant of graphene showed variation of 66% by changing AIREBO parameters only by 0.5%. Based on the sensitivity analysis results, a new robust version of each IP (AIREBO/EAM) was developed using Bayesian methodologies. Using samples from the resulting posterior distribution, MD simulations were performed and error bars for each property was obtained. The variance in the properties was within experimental tolerance exhibiting the reduction in sensitivity for both the material systems. It can be challenging to obtain a single classical IP to describe the interactions involved in multi-element systems. Various machine learning based potentials have been proposed to overcome this limitation however their computational cost can be high. The proposed model approximates the energy/forces using a linear combination of random features at a lower computational cost. This study provides results for three classes of materials, namely two-dimensional materials, metals, and semiconductors. Force and energy predictions made using the proposed method are in close agreement with density functional theory calculations, with training time that is 96% lower than standard kernel models. This study also develops IPs for High Entropy alloys based on random features. MD simulations for mechanical and thermal properties are within 7% of the corresponding DFT values. Complex interactions present at high temperatures were also correctly identified by the proposed IP.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.003
metaresearch head score (Gemma)0.004
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesMeta-epidemiology (narrow), Scholarly communication, Insufficient payload (model declined to judge)
Consensus categoriesMeta-epidemiology (narrow), Insufficient payload (model declined to judge)
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Simulation or modeling · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.475
Threshold uncertainty score1.000

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0030.004
Meta-epidemiology (narrow)0.0010.001
Meta-epidemiology (broad)0.0020.001
Bibliometrics0.0010.001
Science and technology studies0.0010.000
Scholarly communication0.0020.000
Open science0.0020.001
Research integrity0.0010.001
Insufficient payload (model declined to judge)0.0040.002

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.035
GPT teacher head0.363
Teacher spread0.328 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it