QDB, the Quantemol Database of Plasma Processes: Current Status and Recent

DevelopmentChristian Hill, Quantemol LTD

1. Data in QuantemolDB

2. Using QuantemolDB

3. Quantemol “Chemistries”

4. The QuantemolDB API

5. QDB Secure

Summary

Current Data Types

• Electron collision cross sections (10000+)• Collisional process rate coefficients (2600+)• Reaction probabilities• Sticking probabilities

Data in QuantemolDB

Current Statistics (as of 11 September 2017)

• 12718 Data Sets• 1752 “Stateful” species• 32 Chemistries

QuantemolDB Data Model

• Species and State description• Codified in a text-based mini-language

• Parsed by open source software library

• “Reactions” (– mostly, collisional processes)• Data Sets

• Tabular (– mostly, energy-dependent cross sections)

• Parameters (– mostly, Arrhenius-style parameters)• Chemistries

• Collections of Reaction Data Sets• Self-consistent• Validated

• Search by species• Search by combination of reactants or products• Search by citation (data source)

Using QuantemolDB

• Comparison of up to 5 cross sections on an interactive chart• Download data in different formats• Rate and comment on data sets• Rate and comment on Chemistries

• Upload data sets (approved users only)• Assign new reaction species (approved users only)• Add citations / source (approved users only)

Data Sheets• Interactive chart (for tabular data)

• Zoom / pan / rescale

• Uncertainties shown as shaded regions• References

• Full bibliographic citation with links to journal articles • Downloads

• .xsec and .csv text file downloads• User Rating

• 1–5 star ratings provided by users• Comments

• Free-text comments and notes from users

Data Set Rating

In addition to user-provided ratings, many data sets are given a 1–5 star evaluation by Quantemol experts, on the following basi

“Stateful” species have a chemical formula and may be associated with one or more states; the following types of state are supported:• Atomic and molecular configurations• Atomic and molecular term symbols• Diatomic and polyatomic vibrational states• Rotational states• Generic key-value pairs• Energy / wavelength / frequency• Solid disposition (amorphous, crystalline, polycrystalline)• Surface characterisation (Miller indices, adsorbed layers, reorganisation

information)

Chemistries and evaluation

Chemistries and evaluation

Each Chemistry is supported by*:• Notes and validation information• Downloads in “qdat” format or in a ZIP archive of individual files• Reaction list, with links through to Data Sheets• Comments page for notes and questions

* Some functionality is restricted to users with “Gold” status only.

Application Programming Interface (API)

QuantemolDB exposes an API to retrieve reaction datasets and chemistries by GET request to the URL

https://www.quantemoldb.com/reactions/api/

An active and valid API key is required.

Advantages:

• Automated retrieval of QDB data by software

• Latest data versions guaranteed

Application Programming Interface (API)

• Supported output formats:

• “Native” qdat / xsec format

• Comma-separated text format

• ChemKIN / LXCat, COMSOL-compatible format

• QML (an XML format), [planned]

• Plasma simulation codes can use the API to determine which Chemistries are available and which Reactions are in each Chemistry

Application Programming Interface (API)

Example queries:

https://www.quantemoldb.com/reactions/api/?key=XXXX-XXXX-XXXX-XXXX&datasets=7,9,2789,346

[Returns data in native qdat/xsec format for reaction datasets identified by ids 7, 9, 2789 and 346]

https://www.quantemoldb.com/reactions/api/?key=XXXX-XXXX-XXXX-XXXX&xsec_format=csv&arrhenius_format=chemkin&qsymbols=AR,AR^,H,AR2^

[Returns all datasets involving only species Ar+, H and Ar2+ in CSV format (for tabular

cross section data) and ChemKIN format (Arrhenius parameter data)]

https://www.quantemoldb.com/reactions/api/?key=XXXX-XXXX-XXXX-XXXX&chemistry_id=4

[Returns all data comprising the Chemistry with ID 4 (Ar/H2)]

QDB Secure

QDB Secure is a planned database service for the private storage of commercially-sensitive data.

There are two main applications:

(1) Local storage of QDB data, and the facility to add to it privately, creating a customized, local database of plasma data.

•Local QDB database can “pull” the latest Quantemol data via the API

•Species metadata (e.g. enthalpies, Lennard-Jones parameters) on local data may be obtained securely through the API

QDB Secure

QDB Secure is a planned database service for the private storage of commercially-sensitive data.

There are two main applications:

(2) Local and private storage of generic data, envisioned to be experimental results e.g. etch rates, deposition rates in ALD applications

• Allows a structured and searchable way to store research data relating to plasma processes

• Can be linked to QDB Chemistries for theoretical modelling and prediction

Publications

J. Tennyson et al., “QDB: a new database of plasma chemistries and reactions”, Plasma Sources Science and Technology 26, 055014 (2017).

References and Acknowledgements

Powerbase

Partial funding was received from the UK STFC under grants ST/M007774 and ST/K004069, and from the

Powerbase project. Powerbase has received funding from the Electronic Component Systems for

European Leadership Joint Undertaking under grant agreement No 662133. This Joint Undertaking

receives support from the European Union’s Horizon 2020 research and innovation programme and

Austria, Belgium, Germany, Italy, Netherlands, Norway, Slovakia, Spain, United Kingdom.

Thanks

Mayya Bondarevskaya, whose MSc project “Development of pyvalem and pyqn Python libraries”

provided code for the description of species and physical quantities in QuantemolDB