<div dir="ltr"><div>Hi,</div><div>Both way it should work, as you mentioned above. You can check the volume in your output files.</div><div><br></div><div>Thanks,</div><div>Rita <br></div><div><br></div><div><div><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><span style="font-family:georgia,serif">Rita Maji</span></div><div><span style="font-family:georgia,serif">Research scholar</span></div><div><span style="font-family:georgia,serif">School of Physical Sciences</span></div><div><span style="font-family:georgia,serif">National Institute of Science Education and Research</span></div><div><span style="font-family:georgia,serif">Bhubaneswar, 752050</span></div><div><span style="font-family:georgia,serif">Odisha, India</span><br></div></div></div></div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Apr 3, 2020 at 4:38 PM rekha sharma <<a href="mailto:rekha1997jpr@gmail.com">rekha1997jpr@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><font size="4" face="georgia, serif" color="#000000">Dear All,</font><div><font size="4" face="georgia, serif" color="#000000"><br></font></div><div><font size="4" face="georgia, serif" color="#000000">Hope you are healthy during this hard time of COVID-19.</font></div><div><font size="4" face="georgia, serif" color="#000000"><br></font></div><div><font size="4" face="georgia, serif" color="#000000">I want to do some scf calculations at a slightly larger volume and smaller volume than the equilibrium volume to compute gruneisen parameter.</font></div><div><font size="4" face="georgia, serif" color="#000000">I tried with two different approaches to calculate the volume and for both the cases my celldm's are different.</font></div><div><font size="4" face="georgia, serif" color="#000000">I am seeking your expert guidance to choose the approach which is correct one.</font></div><div><font size="4" face="georgia, serif" color="#000000"><br></font></div><div><font size="4" face="georgia, serif"><span style="color:rgb(0,0,0)">My system is with ibrav=-12 where the QE.in file adopts below geometry.</span><br></font></div><div><font size="4" face="georgia, serif"><span style="color:rgb(0,0,0)">...</span><br></font></div><div><font size="4" face="georgia, serif" color="#000000">&SYSTEM<br></font></div><div><font size="4" face="georgia, serif" color="#000000"> ecutrho = 560<br> ecutwfc = 70<br> ibrav = 0<br> nat = 20<br> ntyp = 3<br></font></div><div><font size="4" face="georgia, serif" color="#000000">/</font></div><div><font size="4" face="georgia, serif" color="#000000">...</font></div><div><font size="4" face="georgia, serif" color="#000000">CELL_PARAMETERS angstrom<br></font></div><div><font size="4" face="georgia, serif" color="#000000"> 6.962369043 0.000000000 -0.001331115 (This 0.001331115 is deviated after vc-relax)<br> 0.000000000 7.866710453 0.000000000<br> -6.770669758 0.000000000 9.932067578<br></font></div><div><font size="4" face="georgia, serif" color="#000000"><br></font></div><div><font size="4" face="georgia, serif" color="#000000"><br></font></div><div><font size="4" face="georgia, serif" color="#000000">In one of the approach I used celldm(1)= 1.870829, 1.88973, 1.908623 [converted values of 0.99, 1, 1.01 in Bohr] for minus, orig and plus volume deviation whereas I kept my cell parameters as such as above</font></div><div><span style="color:rgb(0,0,0)"><font size="4" face="georgia, serif"><br></font></span></div><div><font size="4" face="georgia, serif"><span style="color:rgb(0,0,0)">In this case the </span>celldm's<span style="color:rgb(0,0,0)"> are </span><br></font></div><div><font size="4" face="georgia, serif" color="#000000"> Minus original Plus<br clear="all"></font><div><font size="4" face="georgia, serif" color="#000000">celldm(1)= 18.5821709383, 18.7699067564, 18.9575631139<br>celldm(2)= 0.7920102607, 0.7920102607, 0.7920102607<br>celldm(3)= 0.7009623470, 0.7009623470, 0.7009623470<br>celldm(5)= 0.0191088849, 0.0191088849, 0.0191088849</font></div><div><font size="4" face="georgia, serif" color="#000000">In this case celldm's 2,3,5 are same.</font></div><div><font size="4" face="georgia, serif" color="#000000"><br>while in other case I changes Crystal lattice vectors V1 only by +/-1% without defining celldm under &SYSTEM</font></div><div><span style="color:rgb(0,0,0);font-family:georgia,serif;font-size:large">In this case my celldm's are</span><br></div><div><font size="4" face="georgia, serif" color="#000000"> minus 1% Orig Plus 1%<br>celldm(1)= 18.7677900578, 18.7698683460, 18.7728685334<br>celldm(2)= 0.7920979656, 0.7920102607, 0.7918836856<br>celldm(3)= 0.6940295700, 0.7009623470, 0.7078588256<br>celldm(5)= 0.0120986705, 0.0191088849, 0.0261162263<br>here celldm's 2,3,5 are different and celldm(1) is different than I have in the case 1st.</font></div><div><font size="4" face="georgia, serif" color="#000000"><br></font></div><div dir="ltr"><div dir="ltr"><div><font size="4" face="georgia, serif"><font color="#000000">Can you please guide me how to set my volume at </font>slightly larger volume and smaller volume than the equilibrium volume ?</font></div><div><font size="4" face="georgia, serif" color="#000000">Your help will be very helpful for me and I will be grateful to you all.</font></div><div><font size="4" face="georgia, serif"><br></font></div><div><font size="4" face="georgia, serif" color="#000000">Thank you very much in advance.</font></div><div><font size="4" face="georgia, serif" color="#000000"><br></font></div><div><font size="4" face="georgia, serif" color="#000000">Best wishes</font></div><div><font size="4" face="georgia, serif" color="#000000"><br></font></div><div><font size="4" face="georgia, serif" color="#000000">Ms. Rekha</font></div><div><span style="color:rgb(0,0,0)"><font size="4" face="georgia, serif">Teaching Assistant,</font></span></div><div><font size="4" face="georgia, serif" color="#000000">Department of Physics</font></div><div><font size="4" face="georgia, serif"><span style="color:rgb(0,0,0)">RK college, Jaipur, </span><span style="color:rgb(0,0,0)">India<br></span></font></div></div></div></div></div>
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