[Pw_forum] Reply to: negatives frequencies phonon calculation

[Muthu V]

Hello ZAARI

I am also face the same problem in calculation el-ph coupling constant for
Hesuler systems
i tried in the following ways ( though problem still remain anyway for your
system one may solve this problem)

1. check whether your getting -ve frequency in ph.x run
2. increse k point grid in scf and nscf runs ( but 2x2x2 is enough in
epsilon,
     i think )
3. reduce  tr2_ph in el-ph calculation (ph.x)



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*Muthu.V  ​Project FellowDept. of Theoretical Physics​Madurai Kamaraj
Universit*


*​y India*
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