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Hi Marks,<br><br> Thanks for your reply. Let me clarify my question little bit more. <br><br>1) I have optimized the slab using mini. <br><br>2) I have took this optimized case.struct file from mini calculation, initialized <br> a job for wein2k and run scf calculation.<br><br>But when I check the force on the same atom here is what I get.<br><br>case-1: From mini calculation: <br>grep :FGL073 *mini|tail -1<br>:FGL073: 73.ATOM 0.233000000 0.045500000 4.378500000 total forces<br><br>case-2: From scf calculation: <br>grep :FGL073 *scf | tail -1<br>:FGL073: 73.ATOM -1.725500000 -0.171500000 -301.077000000 partial forces<br><br>My question is why there is difference in force even though in both cases I am using the same<br>structure. In the 2nd case, I have slightly larger RMT and k points. Is it the reason for this <br>difference or I am comparing totally different things.<br><br>Thanks,<br>Fhokrul<br><br><br><div><hr id="stopSpelling">Date: Tue, 21 Jun 2011 22:18:38 -0500<br>From: L-marks@northwestern.edu<br>To: wien@zeus.theochem.tuwien.ac.at<br>Subject: Re: [Wien] difference in forces from mini and scf calculations<br><br>You do not provide enough information, so all amyone can do is guess.<BR>
My guess: you are confusing the valence corrected forces (total at the end of case.scfm) and the uncorrected forces (partial). Mini works with the corrected forces.<BR>
<div class="ecxgmail_quote">On Jun 21, 2011 8:40 PM, "Md. Fhokrul Islam" <<a href="mailto:fislam@hotmail.com">fislam@hotmail.com</a>> wrote:<br>> <br>> Hi Prof Blaha,<br>> <br>> I optimized a slab using mini and it worked fine (forces on atoms were reasonably small) . <br>
> But when I used the optimized structure from mini calculations and run scf calculations (with <br>> energy and charge convergence) the forces on atoms increases even after energy is converged. <br>> So my questions are:<br>
> <br>> 1. why forces increases even though I am using exactly the same structure from mini calculations?<br>> <br>> 2. how does it effect the calculated properties such as DOS, magnetic moments? I mean should I<br>
> trust these numbers that I have calculated from scf calculations?<br>> <br>> I have tried looking for the answer in the mailing list but unfortunately I couldn't find one. I would<br>> appreciate any comment from you.<br>
> <br>> <br>> Thanks,<br>> Fhokrul<br>> <br>> <br></div>
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