Hello!!!
I am a novice in quantum espresso, so I need your help in this regard.
We are currently working on the 1x1x1 Ni3Mo (001) surface, to find out the change in the Gibb's free energy when water is adsorbed on the surface.
However, it has been understood that a vacuum needs to be created along z-axis and the crystal needs to be optimized using cell_dofree = '2Dxy' in vc-relax input file.
However, the dyn1 file produces negative frequency in the order of -31.48 [cm-1] , however the .dyn2 file produces negative frequency in the order of -3338.05 [cm-1]!!!!
We are using cell_dofree- '2Dxy' to retain the all the angles same and also at the same time to make sure that vacuum space is kept constant at 20A
Please suggest any solution, so we can move ahead in our project.
PS: Please find attached following files:
1. scf file (before vc_relax)
2. vc-relax file
3. scf file (before phonon calculation)
4. phonon calculation file
5. .dyn1 file obtained during phonon calculation
6. .dyn2 file obtained during phonon calculation
Waiting for the valuable responses.
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Thanks an Regards
Ambasta Vipulkumar Sanjaykumar
Undergraduate researcher
Hello Vipul Kumar Ambasta , If you are only computing the phonon dispersion curve, why are you checking for imaginary frequencies of each dyn? Dyn is basically lattice vibration and it is clear that the starting frequency of any material is generally very odd and after certain time, it settles down to periodicity. And in your dyn files, the frequencies are following the positivity.
Hello Shivam Kansara , really sorry for the late reply. We had restarted the calculations, however as it was large calculation, it shall take few more days to complete.
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