Re: [AMBER] resp charge calculation

From: FyD <fyd.q4md-forcefieldtools.org>
Date: Thu, 09 Aug 2012 18:45:31 +0200

Dear Jit,

Concerning your question:

> Can the esp charge be regarded as the resp charge?

- You should first read the following papers:
http://q4md-forcefieldtools.org/RED/reference.php
U.C. Singh & P.A. Kollman J. Comput. Chem. 1984, 5, 129-145.
    vs
W.D. Cornell, P. Cieplak, C.I. Bayly & P.A. Kollman J. Am. Chem. Soc.
1993, 115, 9620-9631.
C.I. Bayly, P. Cieplak, W.D. Cornell & P.A. Kollman J. Phys. Chem.
1993, 97, 10269-10280.
P. Cieplak, W.D. Cornell, C.I. Bayly & P.A. Kollman J. Comput. Chem.
1995, 16, 1357-1377.

- Then, you could compare RESP vs ESP charges from R.E.DD.B.
http://q4md-forcefieldtools.org/REDDB/
http://q4md-forcefieldtools.org/REDDB/download.php

-- R.E.DD.B. code (if known)
-- Molecule keyword Organic molecule
-- Molecule name
-- Author lastname
-- Theory level/Basis set

Result(s) for search by Molecule keyword Organic molecule

Project name Organic solvent
Project code W-46 RESP Connolly surface
http://q4md-forcefieldtools.org/REDDB/projects/W-46/
Project name Organic solvent
Project code W-47 RESP CHELPG
http://q4md-forcefieldtools.org/REDDB/projects/W-47/
Project name Organic solvent
Project code W-48 ESP Connolly surface
http://q4md-forcefieldtools.org/REDDB/projects/W-48/
Project name Organic solvent
Project code W-49 ESP CHELPG
http://q4md-forcefieldtools.org/REDDB/projects/W-49/

- You could run R.E.D. Server and generate RESP (for instance by
selecting the RESP-A1A charge model) vs ESP charges (vs the ESP-A1
charge model) for your molecule.
See http://q4md-forcefieldtools.org/REDS/popup/popkeyword.php

regards, Francois



Quoting jit mukherjee <jitiitkgp.gmail.com>:

> Dear Amber Users,
>
> In the website page http://www.teokem.lu.se/~ulf/Methods/resp.html, the
> method of calculating the resp charge using Turbomole is given:
>
> RESP with Turbomole
>
> 1. Optimise the structure with QM.
>
> 2. If it is an UHF calculation, you need to have natural orbitals. If
> you do not:
> Insert into the control file the following keywords and rerun ridft
> (dscf):
> $natural orbitals file=natural
> $natural orbital occupation file=natural
>
> 3. Run makepoints to get the points where you will calculate the
> electrostatic potential (ESP).
> Select Turbomole (t), Ball (b), 3.0, 0.3, ChelpG (c), 10000, 8 , and
> Turbomole (non-default values highlighted).
> This gives the file esppoints.
> Note that moloch only writes out at the most 10 000 ESP points. If you
> want more than that, you need to construct several files and concatenate
> the results.
> Therefore, you should probably modify the distance between the points
> (in green above), until you get approximately 10 000 points.
>
> Old version (<5.8):
>
> 4. Insert the suggested rows into the control file (in the beginning to
> avoid already existing keywords).
>
> 5. Run moloch (RHF) or moloch2 (UHF) to get the potentials and also the
> Mulliken charges.
> moloch2 is stupid and does not copy the file esppoints to the new
> directory. Therefore, you have to do:
> moloch2
> cd moloch_n_dir
> cp ../esppoints .
> moloch2
> The calculation takes ~30 minutes and the result is in
> moloch_n_dir/moloch.out.
>
> 6. This file can be read by changepot as detailed
> above<http://www.teokem.lu.se/~ulf/Methods/resp.html#changepot>
> .
>
> With the new (>5.7) version of Turbomole, some changes are needed:
>
> 1. Insert in the control file
> $pointval geo=point pot fmt=xyz
>
> and then the list of coordinates from the file esppoints
> 2. Run
> ridft -proper >logm
> 3. The results is in the file tp.xyz
>
>
> It seems that it is the esp charge that is calculated by this procedure.
> Can the esp charge be regarded as the resp charge?
>
> Regards,
> jit



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Received on Thu Aug 09 2012 - 10:00:03 PDT
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