Ossia is a Monte Carlo program for the study of atomic ordering in crystalline materials. This community is designed as the public face of the program, giving access to the code, a description of the code, and (in time) full help information.

The basic method assumes that the energies associated with ordering can be represented by a mathematical formula, and in general it is anticipated that this will be a relatively simple representation. The standard model is for the energy associated with a pair of atomic sites to be a linear function of their site occupancy, although more sophisticated models are possible.

Ossia is written in Fortran95. It is designed for running on a single processor, with one state point per run. Thus it is ideal for running in a cluster or grid computing environment. Ossia produces an output XML file (using the Chemical Markup Language) to aid data analysis.

atomic ordering, cation ordering, Monte Carlo, order/disorder, ossia, phase transitions, solid solutions