[QE-users] Why do I get multiple imaginary frequencies using nat-todo in QE 6.4

[Yang-Caiyu]

从 Windows 版邮件发送
Dear all,
　　I have been running the frequency calculation of transition state of NH3* → NH2* + H* (* means the substances adsorbed on the Pt(111)). In the calculation process, I fixed Pt atoms by using nat-todo except the NH3 molecule and 2 Pt atoms bonded with it. But I get the results obtained 18 real frequencies and 18 imaginary frequencies. The results are as follows:
　　
**************************************************************************
　　     freq (  1 -  1) =       -494.9  [cm-1]   --> A               I+R
　　     freq (  2 -  2) =       -224.9  [cm-1]   --> A               I+R
　　     freq (  3 -  3) =       -204.8  [cm-1]   --> A               I+R
　　     freq (  4 -  4) =       -127.3  [cm-1]   --> A               I+R
　　     freq (  5 -  5) =       -102.5  [cm-1]   --> A               I+R
　　     freq (  6 -  6) =        -77.1  [cm-1]   --> A               I+R
　　     freq (  7 -  7) =        -66.7  [cm-1]   --> A               I+R
　　     freq (  8 -  8) =        -48.3  [cm-1]   --> A               I+R
　　     freq (  9 -  9) =        -38.3  [cm-1]   --> A               I+R
　　     freq ( 10 - 10) =        -12.9  [cm-1]   --> A               I+R
　　     freq ( 11 - 11) =         -6.2  [cm-1]   --> A               I+R
　　     freq ( 12 - 12) =         -2.8  [cm-1]   --> A               I+R
　　     freq ( 73 - 73) =         86.1  [cm-1]   --> A               I+R
　　     freq ( 74 - 74) =        221.7  [cm-1]   --> A               I+R
　　     freq ( 75 - 75) =        313.7  [cm-1]   --> A               I+R
　　     freq ( 76 - 76) =        439.3  [cm-1]   --> A               I+R
　　     freq ( 77 - 77) =        504.5  [cm-1]   --> A               I+R
　　     freq ( 78 - 78) =        692.8  [cm-1]   --> A               I+R
　　     freq ( 79 - 79) =        745.6  [cm-1]   --> A               I+R
　　     freq ( 80 - 80) =        833.3  [cm-1]   --> A               I+R
　　     freq ( 81 - 81) =       1123.9  [cm-1]   --> A               I+R
　　     freq ( 82 - 82) =       1434.7  [cm-1]   --> A               I+R
　　     freq ( 83 - 83) =       3250.8  [cm-1]   --> A               I+R
　　     freq ( 84 - 84) =       3377.1  [cm-1]   --> A               I+R

I want to know what’s wrong in my calculation process? And my input files are available by the following link.

Thanks in advance

Caiyu Yang
Beihang University

https://www.aliyundrive.com/s/MeXbhArWjLL
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20221118/4ba6e486/attachment.html>