Subject: CCL:deuterated compounds in gaussian98

From: "Jens Spanget-Larsen" <[email-masked]>
Date: Mon, 12 Aug 2002 10:03:29 +0100

Viktor Hornak:

> I'd like to use Gaussian98 for comparing vibration spectra of
> non-deuterated and deuterated form of the compound. I found
> "ReadIsotopes" option of "Freq" keyword and tried to use it like
> this (with isotope masses for all atoms after coordinate section):
> 
> #P HF/6-31G* OPT FREQ(Raman,ReadIsotopes)
> 
> I was wondering if someone could advise: (1) if such calculations
> "make sense" and (2) why I don't see anything like "H-2" (only H-1)
> in the output file under heading "Isotopes:". Any help is
> appreciated... 

Dear Viktor,
you should check that the right isotope masses appear in the G98 
printout with the following layout:

  ..
 Atom  6 has atomic number  6 and mass  12.00000
 Atom  7 has atomic number  8 and mass  15.99491
 Atom  8 has atomic number  1 and mass   2.01410
  ..

This indicates, e.g., that atom nr. 8 is hydrogen with nuclear mass 
2.01410, i.e., deuterium. That the calculation "makes sense" should, 
of course, also be evidenced by the computed vibrational frequenced, 
for example, CD-stretches should show the appropriate shift relativce 
to CH-stretches, etc. - Good Luck!

Jens >--<

NB! Please note new mail address: <[email-masked]>
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
JENS SPANGET-LARSEN         Office:         +45 4674 2710
Department of Chemistry     Fax:            +45 4674 3011
Roskilde University (RUC)   Mobile:         +45 2320 6246
P.O.Box 260                 E-Mail:        [email-masked]
DK-4000 Roskilde, Denmark   http://virgil.ruc.dk/~spanget
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=