[gmx-users] mixed solvent density

[Anton Feenstra]

John Simms wrote:

> Hi All,
> This may be naive, but i would like to set up a mixed solvent box which
> contains chloroform, methanol and water in a 4:4:1 ratio. How do I calculate
> the density of a mixed solvent and from this i would then be able to scale
> the box correctly.

You can't calculate it - best is to measure it. You should, however, setup
the appropriate mixed system and let its pressure equilibrate in an MD
simulation. That way, you can verify if the density in the simulated system
matches that which you have measured. (Of course, you can scale the box
initially to the 'correct' measured density - but after that you must still
let it equilibrate!)


-- 
Groetjes,

Anton
  _____________ _______________________________________________________
|             |                                                       |
|  _   _  ___,| K. Anton Feenstra                                     |
| / \ / \'| | | Dept. of Pharmacochem. - Vrije Universiteit Amsterdam |
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| \_/ \_/ | | | Tel: +31 20 44 47608 - Fax: +31 20 44 47610           |
|             | Feenstra at chem.vu.nl - www.chem.vu.nl/~feenstra/       |
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