[CPMD-list] printing out the fictitious velocities for CPMD simulations

[Hakan Gunaydin]

Dear CPMD users,

I am interested in running CPMD simulations. My problem is with the
fictitious mass. I would like to be able to determine what is the upper
limit of the fictitious mass that I can use for any given system and still
conserve the adiabaticity of the ionic - electronic separation.

As far as I know, the way to check the adiabatic separation between the
ionic motion and electronic motion is to compare the power
spectrum of the wavefunction due to fictitious mass to the power spectrum
of the sytem itself. As long as the highest frequency of the actual system
is well separated from the lowest electronic frequency, I can use the
given fictitious mass.

My question is, is there a way to print out the fictitious velocities for
the motion of the wavefunction for CPMD simulations? If I know what the
velocities are, I can use the Fourier transform of the velocity
autocorrelation function to get the electronic power specturum. Or is
there an alternative (more trivial) approch to find the upper limit for
the fictitious mass?

Best Regards,
-Hakan