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<div>Dear experts,</div><div><br></div><div>I'm doing a phonon calculation for a defected bcc-iron (a supercell with one impurity atom).</div><div>The cell has 54 atoms, so I thought it should be okay with gamma only q-point calculation. Force relaxation has been done, and was restarted twice.</div><div>After the calculation finished, from the dyn1 file I saw three 193 THz frequencies (of the same representation), which appear to be crazy as the frequencies are expected to be around 10 THz.</div><div><br></div><div>What has been going on with the calculation?</div><div>The calculation was interrupted twice, and the "recover" option was used to continue it. Does that has anything to do with the large value of the phonon frequency?</div><div><br></div><div>I also got some negative frequencies, which also appear unexpected (it should be rather stable with 53 Fe atoms...). Are there some general clues about the implication of this kind of results?<br>
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</div><div>Your help is appreciated!</div><div><br></div><div>Yi Wang</div><div><br></div><div>---------------------------------------------------</div><div><br></div><div>Nanjing University of Science and Technology</div>
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