ALLOY DATABASE (search tips)

This page gives hints for effectively searching the alloy database.

Energy diagrams

We have a large number of precalculated energy diagrams. Selecting one of these yields a diagram of the convex hull of energy versus composition. Vertices of the convex hull represent structures that should be stable in the limit of low temperature. Structures whose energy lies above the convex hull will decompose at low temperatures. The energy diagram is thus a predicted phase diagram in the limit of low temperatures.


This option lists all two-component alloy systems for which we have calculated the energy for at least one compound. The numbers in brackets on the selection line indicate the number of compounds studied and give an impression of how thoroughly the energy diagram has been investigated. Be sure to study the plotting symbol definitions.


This option lists all three-component systems for which we have studied at least one compound. The numbers in brackets indicate the number of ternary compounds studied for the given alloy system. Energy data for the pure elements and binaries in their most stable forms is also included. The graph illustrates the convex hull defined above the ternary composition plane. Stable compounds lie at convex hull vertices, which can be identified as junctions of edges. Be sure to study the plotting symbol definitions.

Generalized Searches

You can search for prototypes, Pearson symbols, various interesting models and combinations of chemical species. Selecting more than one entry gives the intersection of matches to the individual selections (i.e. logical "and" is performed). For instance, selecting chemical element C and prototype C6Cr23 yields all results in the database based on the C6Cr23 prototype containing Carbon.

You may specify up to four different elements. Element "any" matches all chemical species. Element "none" restricts the total number of different elements. For example, searching on "C, Fe, any, any" matches all binary and higher order alloy systems containing C and Fe. Searching on "C, Fe, any, none" matches only C-Fe ternary compounds, while "C, Fe, none, none" matches only the C-Fe binary.

Models are various structures constructed by hand, not based on any recognized prototype. Many of these are specific chemical decorations of supercells of simpler structures. Others are quasicrystal-related structures. The tilings are mainly quasicrystalline approximants based on decorations of geometrical tiles. Here B, H and S refer to boat, hexagon and star tiles (not Boron, Hydrogen and Sulfur!). RT refer to rectangle-triangle tilings.