<HTML>
<font style="FONT-SIZE: 10pt; FONT-FAMILY: tahoma">
<div>
</div>
<div>
<br /> Dear Paulatto
</div>
<div>I read your discussion about , how we can sure about stability of the
one layer material. One of your suggestion was to compare the energy of
isolated layer with a layer in bulk, I am working on graphene and
in first step I relaxed my system and compared the result with
graphite. the energy of graphite was higher than graphene. now my question
is, there is van der waals bond in graphite and I've heard DFT
calculations are not suitable for this materials because of its
approximation in potential .Is it correct or some
correction is implemented in Q-E.
</div>
<div>Also during my calculation I realized that when I increased the value
of (celldm(3)=3-10) to attached isolated plane for graphene, there
isn't any noticeable flactuations in total energy, but the values of
subenergies such as hartree, ewald energy,...change extremely,I mean these
terms become large and I think it is not logical.What do you think?
</div>
<div>Best Regards
</div>
<div>Mehrnaz Anvari
</div>
<div>Iran University Of Science & Technology
</div>
<div>
<br />
</div></font>
</HTML>