:orphan: .. status publishable .. product UNCLE .. sectionauthor Gerhard .. SME David .. PR Walter .. TW Kathy .. date 2018 .. _UNCLEDTS: |medea| |muncle| Explore Phase Stability, Bridge the Length Scales ---------------------------------------------------------------------- .. admonition:: **At-a-Glance** |medea|\ :sup:`®`\ [#TM]_ *UNCLE* (UNiversal CLuster Expansion) [#UNCLE]_\ :sup:`,`\ [#MuellerReview]_ expands access to materials and properties at the mesoscopic and microscopic scales, while retaining the predictive power and accuracy of *ab-initio* Density Functional Theory (DFT). Explore order-disorder phenomena and phase segregation processes as a function of temperature and composition, and predict additional scalar properties such as band gaps or bulk moduli. **Key Benefits** * Models systems containing millions of atoms with DFT accuracy * Train and evaluate cluster expansions to predict energies and secondary scalar properties such as band gaps or bulk moduli. * Streamlined, user-friendly setup within the |medea| |menvironment| * Automated, workflow-based refinement of cluster expansions * Efficiently manage hundreds of input structures * Gain insight with intuitive graphical analysis and visualization tools * Flexibly split and restart complex calculations * Extend and expand existing cluster expansions with ease Cluster Expansion with |medea| |muncle| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ |medea| |muncle| lets you determine stable multi-component crystal structures and rank metastable structures by enthalpy of formation, while maintaining DFT accuracy. VASP *ab-initio* calculations are performed on automatically chosen sets of small models to obtain effective interaction parameters. Use these in a Monte Carlo simulation to capture the configurational complexity of real materials at different temperatures. :myquote:`On the one hand, cluster expansions are used to treat systems ranging from a few up to a million atoms without giving up the accuracy of modern DFT calculations. On the other hand, Monte Carlo simulations permit us to study finite-temperature properties such as short range order phenomena or mixing enthalpies.` :myquotee:`Stefan Müller (introduction of [3])` .. figure:: /Datasheets/images/UNCLE-picture0.png :align: center Ground state diagram (convex hull) for the Cr-Ni system Tight integration with |medea|\ 's job control guarantees ease of use, stability, and fault tolerance. Monitor progress of these fully automated calculations, and use graphical tools to readily visualize results. .. figure:: /Datasheets/images/UNCLE-picture1.jpg :align: center Monte Carlo temperature profile (heating and cooling curves) and simulation cells for a 5 component high-entropy alloy Properties from |medea| |muncle| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ * Ground state diagram (convex hull) * Structures of stable phases * Vacancy concentrations * Miscibility * Random mixing energy * Phase stability as a function of temperature and concentration * Solubility * Order-disorder transition temperature * Microstructure * Short range order parameter * Surface segregation * Surface coverage of adsorbents * Secondary scalar properties such as mechanical, optical or electronic properties Computational Characteristics ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ * Use Genetic Algorithm or Compressive Sensing * Full integration with |medea| |mvasp| and other modules * High-throughput using the |medea| |jobserver| .. figure:: /Datasheets/images/UNCLE-picture2.png :align: center NiAl alloy: (100) cut through a 1000 x 1000 x 1000 simulation cell superlattice with 2% constitutional vacancies at T = 500K. .. add for a column break, adjust where needed .. raw:: latex \newpage Required Modules ^^^^^^^^^^^^^^^^ * |medea| |menvironment| * |medea| |muncle| * |medea| |mvasp| Find Out More ^^^^^^^^^^^^^ Learn more about |medea| |muncle| applications and examples by watching the webinar |webinaruncle|. Find out more by visiting the |appnotewixpage|: * Adaptive Crystal Structures of Au-Cu Alloy * Structure and Bonding of Boron Carbide .. [#TM] |regTMinfo| .. [#UNCLE] D. Lerch *et al.*, *Modell. Simul. Mater. Sci. Eng.* **17**, 055003 (2009) (`DOI `__) .. [#MuellerReview] S. Müller, *J. Phys.: Condens. Matter* **15**, R1429 (2003) (`DOI `__) .. only:: html :download: :download:`pdf `