Molecular-Dynamic Code to Simulate the Properties of Materials With Covalent
Chemical Bonds (SAGE MD)
Aleynikov A.Yu.,
Nikolai.S.Ganchuk(

), Yermakov P.V., (*)Korkin À.À., Selezenev À.À.
Sarov Open Computing Center, (*)Motorola
Molecular dynamics code SAGE MD is designed for modeling of chemical and
physical properties of materials by the classical molecular dynamics method.
The code has been written in FORTRAN 90, a part of the code has been written
in MS VC++. A friendly user interface has been added to the code. The user
interface allows setting all initial data for SAGE MD code using the dialogues
and menu. The result of all operations with crystal lattice during generation
of initial geometry of MD cell is displayed on the monitor allowing the user
to control the correctness of his/her actions. During setting the initial
geometry of the crystal the following operations may be applied to the
selected part of the crystal lattice: copying, transfer, axis turn to the
specified angle, deletion, scaling, changing of atom type. The user interface
allows also displaying the atoms position in MD cell during calculation, as
well as displaying all calculated values in form of diagrams after calculation
is complete.
The SAGE MD code can be used to model the properties of materials at constant
temperature and/or constant pressure, as well as to simulate the behavior of
material’s crystal lattice exposed to extension or compression. The
calculations of Radial Distribution Function (RDF) and atoms diffusion
coefficient are implemented in the code. Different boundary conditions can be
set during modeling: periodical boundary conditions, free surfaces, and
movable walls. The interatomic interaction model taking into account the
charges distribution on atoms (QEq model) has been incorporated into SAGE MD
code to simulate the properties of the materials with covalent chemical bonds.
The following interatomic potentials are also incorporated into SAGE MD code:
Morse, modified Morse, Bukingham, Embedded Atom Method (EAM),
Stillinger-Weber, Tersoff B, Tersoff C, Maruyama. The code has been tested by
comparison of the MD modeling results with the known experimental values of
the physical characteristics of silicon and silicon oxide.