LeoCrystal. Free download: LeoCrystal.zip (223 Kb) LeoCrystal...

LeoCrystal. Free download: LeoCrystal. zip (223 Kb) LeoCrystal is password protected software application. It means that you need to buy a password to run it on your computer.

Learn more about registration procedure. Minimum requirements: Win95/NT and higher, 64MB RAM,video card recommended. LeoCrystalClick to see in actual size.

Introduction. LeoCrystal is a software program that performs numerical Monte Carlo modeling of reaction on thesurface of the growing crystal for illustrative educational and research purposes.

With the help of this program you can estimate influence of effective geometrical sizes of structure elements of the crystal and thermodynamic parameters of the process on the topology and kinetic of the crystallization.

As soon a process of crystal growth is presented itself in practically all major technology processes an in depth understanding of complexity of it is essential for professional research in different area of applied science.

Particular interest it could be for the nonotechnology investigations permitting off site optimizing design on the molecule scale level. The creative presentation of the surface includes a three-dimensional perspective projection and stereo view.

It makes this software a great illustrative toll for teaching of the concept of phase transition for the students of very broad ranges of initial background.

Theoretical background. Very moderate scientific background is needed to understand a material in this section. Preliminary runs of the program will make a great help to easy accommodate basic concepts.

The crystal growth is a phase transition process with sharp border betweenit and initial feeding phase like a liquid, gas or plasma. The structureelement (molecule) of the crystal could be determined as a minimum partof it when a reaction of incorporating its in the crystal will effect with changing energy of the wholesystem that will be equivalent to the condensation energy of the corresponding massof crystal.

In simple words the molecule is the minimum part of the crystalthat behaves as a whole crystal. The principal difference of behavior of molecules in liquids is based on the principle of the long order in the crystals structure.

Each molecule hasexact position relatively to the other in crystal. In the every moment of time one molecule on the surface of a crystal have twooptions (taking diffusion out from consideration): to get out to initial matter or stay incorporated as a part of crystal.

The same choice is true for the molecule outside ofcrystal in direct closeness to its surface. It can be incorporated intobody of crystal or stay outside.

The model implemented here is based on calculating theseprobabilities for each position on the surface of the crystal and comparingwith the random number to decide what one of three possible events will happen:stepping ahead or back or just staying on its place.

Probabilities of transition of molecule from and in crystal is calculatedon the base of model of thermal activation reaction. It presumes that moleculesperform thermal vibrations and could sometimes occasionally.