[CPMD-list] How can I get vibrational spectrum in centroid-PIMD

[qfzhang]

Hi,
   I am doing some centroid-PIMD calculations now. I wonder how can I get the
vibrational spectrum. I have read some papers on CMD and the Fourier-
transformed centroid position-position time correlation function is often used
and then times another term. But the velocity-velocity correlation function
often use to get the spectrum in common MD. And the centroids in CMD is a
analogy to the atoms in common MD. So can I use it for vibrational analysis?
And how can I do that? 

      Best wishes
                                              Qianfan Zhang
                                               2007-08-17