KIM API version 1.2.0 released


The KIM development team is pleased to announce the release of version 1.2.0 of the KIM application programming interface (API). By conforming to this API, an atomistic simulation code will seamlessly work with any KIM-compliant interatomic model written in any supported language. This release includes a completely redesigned Make system with many new features and benefits, a new NEIGH_RVEC_H NBC, a streamlined scheme for specifying a Model (or Model Driver name) and its associated “model_init()” function name, other minor changes to the api, bug fixes, portability improvements, and some new examples.

Version 1.2.0 is a fully functioning API. It has the following main features:

  • licensed under the Open Source CDDL license
  • support for C, C++, FORTRAN 77, Fortran 90/95
  • partial support for Fortran 2003 (more information available on request)
  • support for static and dynamic linking of programs using the OpenKIM API
  • communication of an arbitrary number of `arguments’ to and from a Model
  • support for multiple particle types
  • enables a simulation code to access and modify Model parameters
  • support for physical units and unit conversions
  • support for six NBC (neighbor list and boundary conditions) methods
  • support for `Model drivers’ (Models that read in parameters)
  • built-in support for virial and Hessian calculations
  • up-to-date documentation

(See the CHANGELOG and README files described below for more information on these features.)

The distribution includes the API code, examples of simulation codes (Tests) and interatomic models (Models) and documentation.

To obtain the code, visit the following page:

and click on the link for the current release of the KIM API on the top of the page. Then do the following:

  1. Unpack the tarball (on Unix/Linux/Mac OSX systems, type: tar zxvf openkim-api-v1.2.0.tgz) which will create the directory openkim-api-v1.2.0
  2. Read the CHANGELOG file in the root directory (openkim-api-v1.2.0/CHANGELOG) to see what is new in the current release.
  3. Read the README file in the root directory (openkim-api-v1.2.0/README).
  4. Install the package. See directions in the INSTALL file in the root directory.
  5. Read the file README in the DOCs directory for a step-by-step guide to learning the API.


If you have problems or questions, send an email with your question and all relevant information to

Your message will be posted to the openkim google group:

The members of the openkim development team actively monitor this forum and will do their best to help you with your question in a timely fashion. This forum is also used to announce minor new releases and bug fixes.

If you plan to work with the KIM API, it is highly recommended that you become a member of the openkim group. (Just go to the above link and click on “Join this group” on the right of the screen.)

(For more information on planned new features, see the TODO file in the API package root directory: openkim-api-v1.2.0/TODO)