Dear users of LAMMPS,
I would like to use LAMMPS to address the following problem
Can anybody help me out in sorting out this issue
I have two metals, say Ti and Ni at T=1400 K (they are in their molten state)
I have X(Ti)=0.50 and X(Ni)=0.50
I would like to calculate the enthalpy of mixing of Ti and Ni at T=1400 K.
Can anybody tell me a general approach for this problem and if it can be done using LAMMPS.
What are the potentials to be used in such cases
Thank you
Suddhasattwa Ghosh
EAM potentials can be used for liquid metals. I suggest
finding a paper in the literature that discusses how
to compute enthalpy of mixing.
Steve
Suddhasattwa,
The computation of enthalpy of mixing for alloys is tall order. But don't worry, it can be done.
You will need to perform free energy calculations.
You best bet is to follow some literature papers as Steve mentioned. You can check the following Mishin papers for detailed guideline
of how to perform free energy calculations to obtain the mixing enthalpies.
(1) P. L. Williams, Y. Mishin and J. C Hamilton, Modelling Simul. Meter. Sci. Eng. 2006; 14 : 817.
(2) Mishin, Y. Acta Mater, 2004; 52: 1451.
In general, you will neeed to write a free energy routine to work with your potential to do this. However, LAMMPS users are now lucky to have a plug in free energy code named PLUMED. The first thing you need to do is download Plumed plug in free energy code and compile it with LAMMPS following the installation instructions and you are good to go. Good luck.
Suleiman.