Andreas, Excellent comparisons, but does your = software come with a free slide-rule and a book of Mathematical tables? lol= David Mannock

On Sunday, July= 8, 2018 9:34 PM, Andreas Klamt klamt|*|cosmologic.de <owner-chemistry-,-c= cl.net> wrote:

=20 =20 =20

Victor,

I am afraid that I have to say that my COSMO-RS method is currently the most accurate method for predicting free energies in solution.

This is based on the following arguments:
1) Accuracy (kcal/mol) on 2343 data from Minnesota DB, see A. Klamt, B. Mennucci, J. Tomasi, V. Barone, C. Curutchet, M. Orozco and F. Javier Luque, Acc. Chem. Res., 2009, 42 (4), pp 489):
    COSMOtherm 0.48 (latest COSMOtherm version 0.40)
    SM8        &= nbsp;        0.52 (fitted on this data s= et!)
    PCM        &= nbsp;    ~ 0.9    (only 3 solvents)
2) relative to force fields: Two benchmarks vs.Force-Field-MD show that the error on DGsolv is only about half of the error of force-field methods.
Force Field Benchmark of Organic Liquids. 2. Gibbs Energy of Solvation by Jin Zhang=E2=80=A0=E2=80=A1, Badamkhatan Tuguldur=C2=A7=E2= =80=A1, and David van der Spoel J. Chem. Inf. Model., 2015, 55 (6), pp 1192=E2=80=931201 (s= ee also the erratum):
~230 DGsolv RMSD: MD 3.7 kJ/mol, ADF-COSMO-RS 2.3 kJ/mol, COSMOtherm 1.7 kJ/mol.
see also: Current Status of the AMOEBA Polarizable Force Field &nb= sp; Ponder et al., J Phys Chem B. 2010; 114(8): 2549:
22 DGsolv RMSD: AMOEBA 2.7 kJ/mol, COSMOtherm has 1.6 kJ/mol RMSD on this small dataset.

3) Blind challenges: COSMO-RS is winner of all the 3 IFPSCs (Industrial Fluid Property Simulation Challenges; AICHE/NIST)

which = were on free energy of transfer (e.g. activity coefficients) and on which COSMO-RS was allowed to participate.

4) Blind challenges: COSMOlogic clearly is best in the = SAMPL5 blind challenge on alkane-water logDs of = 53 dem= anding= drugs= and <= /span>is better than the experimental values. J Co= mput <= /span>Aided Mol Des= (2016). doi:10.1007/s10822-016-9927-y
5) Blind challenges: SAMPL6 on pKa prediction: Two CO= SMOtherm use= rs achieve rank 1 = and 4 (Grimme et al., and a Novartis group). Rank 2 and 3 were data driven increment methods.

Summarizing, SMx methods and COSMO-RS are close to each other on the dGsolv database, but COSMO-RS has a much broader validation, especially in blind challenges.
Force-field based methods seem to have twice the error bars than COSMO-RS. This also applies to the 3D-RSIM and other methods, which require force-fields as input.

Regarding alkaline metals in NH3: It is surely wise to describe the first solvation shell explicitly! What I do not understand: Are the alkaline atoms neutral? Or what is the counterion?

Best

Andreas

Andreas,

An important observation. As solvation is not my field of expertise I
would appreciate a short actualization. What method is curently assumed
to be the most advanced form of treating solvation?

I am currently interested in old 1920's experiments regarding alcaline
metals in liquid NH_3. I was thinking on a mixed method: describe the
alcaline metal plus the first solvation shell as an explicit quantum
cluster model and represent the rest of the liquid as a continuous
dielectric using a cosmo or similar model. What do you think?

This is not an exercise for students, just something for learning
myself. At least right now.

Best regards,
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n"

Prof. Dr. Andreas Klamt
CEO / Gesch=C3=A4ftsf=C3=BChrer
COSMOlogic GmbH & Co. KG
Imbacher Weg 46
D-51379 Leverkusen, Germany

phone  =09+49-2171-731681
fax    =09+49-2171-731689
e-mail =09klamt^_^cosmologic.de
web    =09www.cosmologic.de

[University address:      Inst. of Physical and
Theoretical Chemistry, University of Regensburg]

HRA 20653 Amtsgericht Koeln, GF: Prof. Dr. Andreas Klamt
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