<div dir="auto">Also, the relevance of the results goes as exp(-time*1,000,000) so after 11 years the Professor has probably moved to another country.<div dir="auto"><br></div><div dir="auto">I am 100% certain that you are worrying about details which do not matter:</div><div dir="auto">a) DFT lattice parameters are rarely better than 0.5%.</div><div dir="auto">b) DFT energies are rarely better than 4kJ/atom mole in accuracy.</div><div dir="auto">c) Electronic states are rarely better than 0.1 eV, as DFT is ground state.</div><div dir="auto"><br></div><div dir="auto">Accept that you calculations are only good approximations.</div><div dir="auto"><br></div><div dir="auto">"All things appear and disappear because of the concurrence of causes and conditions. Nothing ever exists entirely alone: everything is in relationship to everything else."</div><div dir="auto"><br></div><div dir="auto">-- Gautama Buddha</div><div dir="auto">In Dwight Goddard, Buddha, Truth and Brotherhood (1934)</div><div dir="auto"><div style="" dir="auto"><div dir="auto"><br></div><div dir="auto">---</div><div dir="auto">Professor Laurence Marks<br></div></div><div data-smartmail="gmail_signature" dir="auto">Department of Materials Science and Engineering<br>Northwestern University<br><a href="http://www.numis.northwestern.edu" target="_blank" rel="noreferrer">www.numis.northwestern.edu</a><br>"Research is to see what everybody else has seen, and to think what<br>nobody else has thought" Albert Szent-Györgyi</div></div><br><div class="gmail_quote" dir="auto"><div dir="ltr" class="gmail_attr">On Sat, Oct 23, 2021, 6:09 AM Gavin Abo <<a href="mailto:gabo13279@gmail.com" target="_blank" rel="noreferrer">gabo13279@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div>
<p>I follow that your lattice parameters a=18.508 Bohr, b=39.835
Bohr, c=40.199 Bohr, α=119.701 degrees, β=103.309 degrees, and
γ=90.0 degrees using the equation at [1] give you<br>
</p>
<p>Volume_triclinic = 18.508 Bohr*39.835 Bohr*40.199
Bohr*sqrt(1-cos(119.701 degrees *(<span>π</span> radians/180
degrees))^2-cos(103.309*(<span>π</span> radians/180 degrees))^2-cos(90.0*(<span>π</span>
radians/180 degrees))^2+2*cos(119.701 degrees *(<span>π</span>
radians/180 degrees))*cos(103.309 degrees *(<span>π</span>
radians/180 degrees))*cos(90.0 degrees *(<span>π</span>
radians/180 degrees))) ≈ 24823 Bohr^3.<br>
</p>
<p>I also remember reading that the :VOL in case.scf is for the
primitive unit cell [2-4].<br>
</p>
<p>Regarding the 20805.429 Bohr^3, I don't seem to be seeing enough
information regarding that. Thus, I'm unable to follow where you
are getting that from.</p>
<p>I have seen the post at [5] describing how a triclinic
optimization could be done.</p>
<p>However, in addition to that post I have read other posts about
how it requires too many calculations for triclinic such that it
not likely reasonably possible to do [6-8].</p>
<p>For example, say your advising professor says he needs a
triclinic optimization one week from now. However, say it takes 1
day to run and complete a single calculation on your initial
triclinic structure. Now, if you fixed b, c, α, β, γ and varied
lattice constant a with four different values you would expect
those calculations to take about 4 days. However, to fully
optimize the structure you would also need to vary b, c, α, β, and
γ as well such that you would need to do 4096 calculations in
total as explained in [5].</p>
<p>Thus, you could estimate that it would take 4096 days or about 11
years (=4096/<span>365.25</span>). So it not possible to meet the
professors deadline, but the calculation is possible but would
take 11 years. However, another problem with that could be that
you run out of hard drive space and cannot afford the cost to buy
more hard drives to store the data from all those 4096
calculations.</p>
<p>Furthermore, if you are like me, where I sometimes mess up my
calculation setup during initialization (init_lapw). I would
probably check the result after 11 years to find out I setup the
calculation wrong and have to start over.</p>
<p>So for me it would probably end up similar to the scenerio in The
Hitchhiker's Guide to the Galaxy where my GIGO [9] mistake during
initialization would end with a result like 42 [10].<br>
</p>
[1] <a href="https://urldefense.com/v3/__https://www.globalsino.com/EM/page3033.html__;!!Dq0X2DkFhyF93HkjWTBQKhk!Em14IGppgbfioraJ-l3bMy9gwwMoftlHrzxjMWzvPLGE8PfWKZv3GTl3xlrwxf0dtnXmlg$" rel="noreferrer noreferrer" target="_blank">https://www.globalsino.com/EM/page3033.html</a><br>
[2]
<a href="https://urldefense.com/v3/__https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg20184.html__;!!Dq0X2DkFhyF93HkjWTBQKhk!Em14IGppgbfioraJ-l3bMy9gwwMoftlHrzxjMWzvPLGE8PfWKZv3GTl3xlrwxf3ka8_EwA$" rel="noreferrer noreferrer" target="_blank">https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg20184.html</a><br>
[3]
<a href="https://urldefense.com/v3/__https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg14487.html__;!!Dq0X2DkFhyF93HkjWTBQKhk!Em14IGppgbfioraJ-l3bMy9gwwMoftlHrzxjMWzvPLGE8PfWKZv3GTl3xlrwxf3SHP8f1Q$" rel="noreferrer noreferrer" target="_blank">https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg14487.html</a><br>
[4]
<a href="https://urldefense.com/v3/__https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg19755.html__;!!Dq0X2DkFhyF93HkjWTBQKhk!Em14IGppgbfioraJ-l3bMy9gwwMoftlHrzxjMWzvPLGE8PfWKZv3GTl3xlrwxf2z1QAvAA$" rel="noreferrer noreferrer" target="_blank">https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg19755.html</a><br>
[5]
<a href="https://urldefense.com/v3/__https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg10777.html__;!!Dq0X2DkFhyF93HkjWTBQKhk!Em14IGppgbfioraJ-l3bMy9gwwMoftlHrzxjMWzvPLGE8PfWKZv3GTl3xlrwxf07_GLANw$" rel="noreferrer noreferrer" target="_blank">https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg10777.html</a><br>
[6]
<a href="https://urldefense.com/v3/__https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg01914.html__;!!Dq0X2DkFhyF93HkjWTBQKhk!Em14IGppgbfioraJ-l3bMy9gwwMoftlHrzxjMWzvPLGE8PfWKZv3GTl3xlrwxf2Xv6IO2w$" rel="noreferrer noreferrer" target="_blank">https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg01914.html</a><br>
[7]
<a href="https://urldefense.com/v3/__https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg10505.html__;!!Dq0X2DkFhyF93HkjWTBQKhk!Em14IGppgbfioraJ-l3bMy9gwwMoftlHrzxjMWzvPLGE8PfWKZv3GTl3xlrwxf1is5Zeqg$" rel="noreferrer noreferrer" target="_blank">https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg10505.html</a><br>
[8]
<a href="https://urldefense.com/v3/__https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg21450.html__;!!Dq0X2DkFhyF93HkjWTBQKhk!Em14IGppgbfioraJ-l3bMy9gwwMoftlHrzxjMWzvPLGE8PfWKZv3GTl3xlrwxf1W4CqnGQ$" rel="noreferrer noreferrer" target="_blank">https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg21450.html</a><br>
<div>[9]
<a href="https://urldefense.com/v3/__https://en.wikipedia.org/wiki/Garbage_in,_garbage_out__;!!Dq0X2DkFhyF93HkjWTBQKhk!Em14IGppgbfioraJ-l3bMy9gwwMoftlHrzxjMWzvPLGE8PfWKZv3GTl3xlrwxf0XPlwD1w$" rel="noreferrer noreferrer" target="_blank">https://en.wikipedia.org/wiki/Garbage_in,_garbage_out</a></div>
<div>[10]
<a href="https://urldefense.com/v3/__https://en.wikipedia.org/wiki/Phrases_from_The_Hitchhiker*27s_Guide_to_the_Galaxy*The_Answer_to_the_Ultimate_Question_of_Life,_the_Universe,_and_Everything_is_42__;JSM!!Dq0X2DkFhyF93HkjWTBQKhk!Em14IGppgbfioraJ-l3bMy9gwwMoftlHrzxjMWzvPLGE8PfWKZv3GTl3xlrwxf0fr_h39g$" rel="noreferrer noreferrer" target="_blank">https://en.wikipedia.org/wiki/Phrases_from_The_Hitchhiker%27s_Guide_to_the_Galaxy#The_Answer_to_the_Ultimate_Question_of_Life,_the_Universe,_and_Everything_is_42</a><br>
</div>
<div><br>
</div>
<div>On 10/23/2021 1:18 AM, Anupriya Nyayban
wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">
<div>Dear Prof. Blaha and Dr. Bhamu,</div>
<div><br>
</div>
<div>Thank you Prof. Blaha for the valuable suggestion and I
have followed all the steps as you have mentioned for the
optimization. But still I have doubt when I am going to
calculate the optimized lattice parameters from the optimized
volume. The initial volume calculated using the lattice
parameters before the volume optimization (values I have
mentioned earlier) is 20805.429 Bohr^3. The scf file (before
the volume optimization) shows the lattice parameters (LATT)
and volume (infact this volume is the volume before inducing
the mixing into the 2*2*2 supercell) to be "a=18.508,
b=39.835, c=40.199 Bohr; α=119.701◦, β=103.309◦, γ=90.0◦" and
"24823.466 Bohr^3", respectively. I am confused about the
initial volume which one I should consider and why is this
dissimiarity?</div>
<div><br>
</div>
<div><br>
</div>
-- <br>
<div dir="ltr" data-smartmail="gmail_signature">
<div dir="ltr">
<div>With regards</div>
<div>Anupriya Nyayban</div>
<div>Ph.D. Scholar</div>
<div>Department of Physics</div>
<div>NIT Silchar<br>
</div>
</div>
</div>
</div>
</blockquote>
</div>
_______________________________________________<br>
Wien mailing list<br>
<a href="mailto:Wien@zeus.theochem.tuwien.ac.at" rel="noreferrer noreferrer" target="_blank">Wien@zeus.theochem.tuwien.ac.at</a><br>
<a href="https://urldefense.com/v3/__http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien__;!!Dq0X2DkFhyF93HkjWTBQKhk!Em14IGppgbfioraJ-l3bMy9gwwMoftlHrzxjMWzvPLGE8PfWKZv3GTl3xlrwxf1NYBI8Pg$" rel="noreferrer noreferrer noreferrer" target="_blank">https://urldefense.com/v3/__http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien__;!!Dq0X2DkFhyF93HkjWTBQKhk!Em14IGppgbfioraJ-l3bMy9gwwMoftlHrzxjMWzvPLGE8PfWKZv3GTl3xlrwxf1NYBI8Pg$</a> <br>
SEARCH the MAILING-LIST at: <a href="https://urldefense.com/v3/__http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html__;!!Dq0X2DkFhyF93HkjWTBQKhk!Em14IGppgbfioraJ-l3bMy9gwwMoftlHrzxjMWzvPLGE8PfWKZv3GTl3xlrwxf1-aL_v_w$" rel="noreferrer noreferrer noreferrer" target="_blank">https://urldefense.com/v3/__http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html__;!!Dq0X2DkFhyF93HkjWTBQKhk!Em14IGppgbfioraJ-l3bMy9gwwMoftlHrzxjMWzvPLGE8PfWKZv3GTl3xlrwxf1-aL_v_w$</a> <br>
</blockquote></div></div>