<div dir="ltr"><div>Dear Matteo,</div>
<div>Got your point and really thanks for the help.</div>
<div>Just one more question....</div>
<div>In scf run if we set tstress = .true., then we also get the pressure. And also we have Etot and V, so can we calculate H taking those Etot and V ??</div>
<div> </div>
<div class="gmail_quote">On Tue, Sep 2, 2008 at 11:02 AM, Matteo Cococcioni <span dir="ltr"><<a href="mailto:matteo@umn.edu">matteo@umn.edu</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid"><br><br>Dear Bipul<br><br>I think all you need to do is computing the equation of state for both<br>phases. In other words you choose a series of lattice parameters (that<br>
may be different for the two phases) and compute the total energy for<br>each of them. In this case for B1 (NaCl) and B2 (CsCl) you don't need to<br>relax the atomic positions for each lattice parameter as you would do in<br>
general. Once you get E(V) for each of the phase, you can use the<br>program ev.x to fit a Murnaghan or a Birch eq. of state in your data.<br> From the equation of state you have chosen you can compute the<br>derivative P=-dE/dV at any V within the interval of your fit. This will<br>
be the pressure on your system. for every value of P<br>you will have V and the corresponding E so you will be able to construct<br>E+PV (enthalpy) for the values of P you have.<br><br>hope this helps,<br><br>Matteo<br>
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<div class="Wj3C7c"><br><br><br><br>Bipul Rakshit wrote:<br>> Hello Everyone,<br>> I want to calculate the enthlapy at different pressures of ScAs in B1<br>> and B2 phase, so that i able to find the transition pressure. Can<br>
> anybody tell me the correct method to do that?<br>><br>><br>> --<br>> Bipul Rakshit<br>> PhD Student,<br>> Barkatullah University,<br>> Bhopal 462026,<br>> MP, India<br></div></div>> ------------------------------------------------------------------------<br>
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</blockquote></div><br><br clear="all"><br>-- <br>Bipul Rakshit<br>PhD Student, <br>Barkatullah University,<br>Bhopal 462026,<br>MP, India<br></div>