Re: CCL:solvation effects over amino acid conformers
- From: "Dr. Andreas Klamt" <andreas.klamt at.at
cosmologic.de>
- Organization: COSMOlogic GmbH&CoKG
- Subject: Re: CCL:solvation effects over amino acid conformers
- Date: Tue, 12 Feb 2002 07:40:49 +0100
I cannot really answer this question for the solvation methods in Gaussian,
but there was a study on this subject by a Danish
group:
?Conformational analysis of cyclic acidic a-amino acids
in aqueous solution - an evaluation of different continuum hydration
models."
by Peter Aadal Nielsen, Per-Ola Norrby, Jerzy W. Jaroszewski, and Tommy
Liljefors,
It was intended for JACS. But I think it is published yet only in the thesis of
Peter Aadal Nielsen.
For several ionic cyclic amino acids the population of several conformations was
carefully measured by NMR and the relative
poulations were converted to free energy differences. Then different solvation
methods have been tested whether they are able to
reproduce the free energy differences.
Method Solvent rms rms (4 points) Max Dev
Model (kJ/mol) (kJ/mol) (kJ/mol)
AM1 SM5.4A 4.6 5.6 9.2
PM3 SM5.4P 13.6 16.2 20.5
AM1 SM2.1 7.4 9.0 16.7
HF/6-31+G* C-PCM 3.1 3.8 5.9
HF/6-31+G* PB-SCRF 4.7 5.8 8.8
AMBER* GB/SA 13.2 16.2 24.3
MMFF GB/SA 18.5 19.9 31.4
BP-DFT/TZVP COSMO-RS 2.2 2.6 4.8
COSMO-RS was evaluated as a blind test !!!
Here COSMO was done with Turbomole, using BP91 and TZVP basis set. After that
the COSMO-RS model was applied, using the program
COSMOtherm from COSMOlogic.
Regards
Andreas
--------------------------------------------------------------------------------
Dr. Andreas Klamt
COSMOlogic GmbH&CoKG
Burscheider Str. 515
51381 Leverkusen, Germany
Tel.: 49-2171-73168-1 Fax: ...-9
e-mail: andreas.klamt at.at cosmologic.de
web: www.cosmologic.de
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