Dimmer reference embedded atom method

Kunio Takahashi1 ( takahak-AT-mep-DOT-titech-DOT-ac-DOT-jp.gif ), Tadao Onzawa2
1,Dept. International Development Eng., Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552, Japan.
2Dept. Mechanical and Control Eng., Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552, Japan.

Embedded atom method (EAM) series (http:/www.eamers.org/) are methods to calculate the energy of multi-atomic systems. They are expected for the calculation of large systems because the methods are based on local density approximation theory and use no eigenvalue calculation. In previous EAM series, bulk structures are used as reference structure, therefore, they show high applicability to bulky systems in principle. Recently, poor applicability of them to cluster or molecular systems has been reported. In the present study, dimmer is employed as the reference structure. Furthermore, the embedding function is modified so that the embedding energy does not increase with increasing electron density at equilibrium reference structure. In dimmer reference EAM (DREAM), the energy can be calculated as a function of binding energy, bond length, and other three parameters. Phase diagram at zero temperature is calculated and the possibility of dimmer reference EAM (DREAM) is discussed.