Materials Cloud, a platform for open computational science

Abstract

Materials Cloud is a platform designed to enable open and seamless sharing of resources for computational science, driven by applications in materials modelling. It hosts (1) archival and dissemination services for raw and curated data, together with their provenance graph, (2) modelling services and virtual machines, (3) tools for data analytics, and pre-/post-processing, and (4) educational materials. Data is citable and archived persistently, providing a comprehensive embodiment of entire simulation pipelines (calculations performed, codes used, data generated) in the form of graphs that allow retracing and reproducing any computed result. When an AiiDA database is shared on Materials Cloud, peers can browse the interconnected record of simulations, download individual files or the full database, and start their research from the results of the original authors. The infrastructure is agnostic to the specific simulation codes used and can support diverse applications in computational science that transcend its initial materials domain.

Fig. 1

Materials Cloud organises its resources in five sections, LEARN, WORK, DISCOVER, EXPLORE, and ARCHIVE, representing different stages of the research life cycle.

Fig. 2

DISCOVER section on “2D structures and layered materials”. The “ID card” of a material displays key computed properties, as well as interactive visualisations of the crystal structure (a), the electronic band structure (b) and more. AiiDA icons link every piece of data to its corresponding node in the provenance graph that can be browsed through the EXPLORE interface shown in Fig. 4.

Fig. 3

DISCOVER section on “Covalent organic frameworks (COFs) for methane storage applications”, presenting almost 70000 COFs assembled in silico, together with their computed properties (a) and atomic structures (b) in the form of interactive figures that mirror those published in the corresponding peer-reviewed paper.

Fig. 4

EXPLORE interface for AiiDA provenance graphs. (a) Interactive view of a calculation node (here representing a run of pw.x code from the Quantum ESPRESSO suite), providing download links for all input and output files. The provenance browser on the right allows jumping to the visualisation of any input or output node of the calculation. (b) Interactive view of the atomic crystal structure returned by calculation (a). The provenance browser indicates that this structure was used in three subsequent calculations. See the supporting information for the complete provenance graph.

Fig. 5

Tools in the WORK section. (a) SeeK-path tool for finding and visualising paths in reciprocal space, here showing the Brillouin zone of InHg. (b) Interactive visualiser for lattice vibrations (adapted from henriquemiranda.github.io/phononwebsite), here of two-dimensional phosphorene. Shown is the phonon eigenvector (left) corresponding to the red dot in the phonon band structure (right).

Fig. 6

AiiDAlab simulation environment. (a) Landing page with an overview of the applications installed. (b) “App store” for managing applications. (c) Application that computes the optimised crystal structure of an input material as well as its electronic band structure along standardised paths. Clicking “Edit App” switches to the source code editor (d) of the underlying Jupyter notebook.

Fig. 7

Education and outreach. (a) MARVEL distinguished lectures available in the LEARN section. (b) Slideshot player with slide synchronisation and slide-based browsing. (c) Simulation codes provided with the Quantum Mobile virtual machine, and deployment schemes for the Desktop and Cloud Edition. (d) Screenshot of the Quantum Mobile desktop.

Fig. 8

Materials Cloud architecture diagram. Independent frontends for LEARN, WORK, DISCOVER, and EXPLORE based on AngularJS are powered by different backends, including AiiDA’s REST API, tools encapsulated in docker containers and a JupyterHub running one docker container per AiiDA user.