CCL:G: Solvent mixtures



Hi Zeynep  Pinar
Strictly speaking, my answer here if you are Gaussian user:
Actually, there is no standard approach for solvent mixtures to you use it directly in Gaussian03/09. A good suggestion is to define the
solvent parameters as a linear combination of the solvents in the proportions of the mixture.  So for
toluene:water in a 4:1 mix use 4/5
of the toluene values plus 1/5 of the water values. 

It is recommended to use the SCRF=SMD approach here but that is not recommended for properties other than solvation free energy. It may be give satisfied results in the case of geometry optimization or energetic properties.  It is especially not recommended for derivative properties because the cavity for the SCRF=SMD model has a number of continuity issues.  So for the default SCRF=IEFPCM model with the smooth cavity you mainly need the dielectric and epsinf.  You would specified EPS & EPSInf in the SCRF input section after the blank line which terminates the structure input and the route will have

%chk=mychk
# SCRF=(Solvent=Generic,Read)
title
structure
SolventName=Mixture
EPS=(Add the value of linear combination of both solvents)
EpsInf=(Add the value of linear combination of both solvents)


Worth trying,
Regards,
Morad


From: Zeynep Pinar p_catastrophe(~)hotmail.com <owner-chemistry.:.ccl.net>
To: "El-Hendawy, Morad Metwally " <m80elhendawy.:.yahoo.com>
Sent: Wednesday, April 25, 2012 11:37 AM
Subject: CCL: Solvent mixtures


Sent to CCL by: "Zeynep  Pinar" [p_catastrophe],[http://hotmail.com">hotmail.com]
Hello,

Can anyone please suggest me how to make a single point calculation in a two solvents mixture environment; namely toluene:water (ratio=4:1) ?

Best regards.



-= This is automatically added to each message by the mailing script =-
To recover the email address of the author of the message, please change
the strange characters on the top line to the .:. sign. You can also
E-mail to subscribers: CHEMISTRY.:.ccl.net or use:
     

E-mail to administrators: CHEMISTRY-REQUEST.:.ccl.net or use
      http://www.ccl.net/cgi-bin/ccl/send_ccl_message

Subscribe/Unsubscribe:
      http://www.ccl.net/chemistry/sub_unsub.shtml
Conferences: http://server.ccl.net/chemistry/announcements/conferences/

Search Messages: http://www.ccl.net/chemistry/searchccl/index.shtml

If your mail bounces from CCL with 5.7.1 error, check:
      http://www.ccl.net/spammers.txt