Hi Marawan,
I've not performed a lot of such simulations, but what you propose sounds
reasonable. I believe the time step has a direct impact on the resolution
of the spectrum. I guess it should be chosen to produce stable dynamics (as
per usual) and to obtain the desired resolution (although I don't know
off-hand the conversion from fs to cm-1). I don't think there is any
difference between IR and Raman other than the observable that is followed.
A (somewhat) recent paper that looked at this: Kaminski, *et al.* *J. Chem.
Theory Comput.* 2010, *6*, 1240-1255.
Although I'm sure there are others.
Regards,
Brian
On Thu, Nov 15, 2012 at 5:13 PM, marawan hussain
<marawanhussain.yahoo.com>wrote:
> Dear AMBER users,
> Thanks for the helpful answers.
> Other question:
> What is the optimum time step i have to print the dipole moment at each
> time from the ORCA-AMBER run to Fourier transform and got the IR spectrum.
> ?..I have read for a similar purpose that it should be 0.25 fs
> (dt=0.00025), is it correct.?
> Can i got the Raman spectra by a similar procedure.?
>
> Regards
> Marawan
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--
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Brian Radak : BioMaPS
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Received on Fri Nov 16 2012 - 09:30:02 PST
