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Sorry after reading again and again there is one question I'm not sure
about.<br>
<blockquote cite="mid20050117144503.S47163-100000@qt.dq.ufscar.br"
type="cite"><><!----><br>
g_energy output gives surface pressure, not surface tension.</></blockquote>
I've been reading the gromac's manual an in 7th character , page 138 ,
first paragraph, it speaks about surface tension, not surface pressure.
In the option list of g_energy also speaks about #Surf*SurfTen. Then
why you say the output is the surface pressure?. If you are right then
where is the value of the surface tension of the water to make this
output in the gromacs program. By the way it then means that you can
only calculate "surface pressure" for monolayers in pure water
systems?. Can you explain me that a little more.<br>
<br>
<blockquote cite="mid20050117144503.S47163-100000@qt.dq.ufscar.br"
type="cite"><>to compute the</> <></><>surface tension you have to
use the standard expression:<br>
<br>
gama = gama_0 - pi<br>
<br>
where:<br>
<br>
gama = surface tension<br>
<br>
gama_0 = pure water surface tension<br>
<br>
pi = surface pressure<br>
<br>
anyway, if you're getting surface pressures 3-fold larger than that<br>
of pure water, then your surface tension is negative, isn't it? if<br>
that happens to be the case, then your systems may be still away<br>
from mechanical equilibrium.<br>
<br>
maybe you could give some more details of your simulations: how did<br>
you assembled each monolayer? how long was each simulation run? if<br>
you plot surface area along the simulation time, is it stable?<br>
<br>
best regards,<br>
<br>
andre'<br>
<br>
/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/<br>
<br>
Dr. Andre' Farias de Moura<br>
<br>
/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/<br>
<br>
Laboratorio de Quimica Teorica<br>
Universidade Federal de Sao Carlos<br>
Sao Carlos - SP - Brasil<br>
<br>
/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/<br>
<br>
Endereco Atual<br>
<br>
Grupo de Quimica Quantica<br>
Instituto de Quimica de Sao Carlos<br>
Universidade de Sao Paulo<br>
Sao Carlos - SP - Brasil<br>
Telefone: 55-16-3373-8055<br>
<br>
/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/<br>
</></blockquote>
<><br>
thank you in advance, Hector<br>
</><>--------------------------------------------------------------------------------------------<br>
Hector Martinez-Seara Monne<br>
<br>
</> Universidad de Barcelona<br>
<br>
Dept. Quimica Fisica<><a class="moz-txt-link-abbreviated" href="mailto:hseara@netscape.net">hseara@netscape.net</a><br>
--------------------------------------------------------------------------------------------<br>
</><br>
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