The gibbs energy of a certain substance.

Hello everyone,

Now I want to calculate the gibbs energy of a substance, such as the gibbs free energy of NaCl in a specific temperature and other conditions. Not the difference of gibbs energy between two systems. But I have not make it yet. Do you have some suggestions? I really appreciate it!

Best wishes,

Wentao Zhou

You really need to decide what sort of method you want to use to do this, for which you'll need to consult a simulation textbook (Frenkel and Smit, for example).

If you wanted to use thermodynamic integration, have a look at compute ti.

For absolute Gibbs energies I suggest Hamiltonian switching (gives you
the G difference to an Einstein crystal, which in turn has a G you can
calculate analytically). I'm currently working on wrapping my work on
that up. If you are interested I can try to get it released. It is
more or less a LAMMPS package and a python script for analysis. Buy as
Niall said, study the Frenkel first to understand what it does and if
it really is what you want.

Hi Daniel,

Thank you for your advice! I will learn the paper of Frenkel firstly and see whether it works to my issue.

Thanks again

Wentao Zhou

That’s not a paper, but the book by Frenkel and Smit - “Understanding molecular simulation: from algorithms to applications”.

Oleg

Wentao Zhou <[email protected]…24…> 3 февраля 2014 г. 21:36:18 написал:

Thank you for reminding. I’m sorry that I only checked my email and didn’t see Niall’s reply in the mailing lists. I read many papers about simulation to calculate the absolute Gibbs energy, but most of them use the MC. It would be really helpful if there are some packages in lammps about this issue. I will read the book and get more information. Thank you all for your suggestion!

Wentao Zhou
Graduate Student
Nuclear Engineering Program
The Ohio State University