Re: [AMBER] How to set water molecule without EPW dummy atom?

From: Maciej Spiegel via AMBER <amber.ambermd.org>
Date: Mon, 27 Feb 2023 09:11:57 +0200

Hello Vinícius,
Thank you for the suggestion! I actually decided to try it just after I submitted the question on the mailing list, and it seems to be working flawlessly!

Thank you again and have a great day!

Best regards
--
Maciej Spiegel, MPharm
Department of Pharmacognosy and Herbal Medicines
Wroclaw Medical University
https://farmaceut.github.io <https://farmaceut.github.io/>
.ORCiD <https://orcid.org/0000-0002-8012-1026> @Publons <https://publons.com/researcher/4419515/maciej-spiegel/>
Reviewer at:
Phytochemistry | Free Radical Research |  Theoretical Chemistry Accounts
Journal of Molecular Modeling | Frontiers in Bioscience-Landmark | Symmetry
> Wiadomość napisana przez Vinicius Wilian Cruzeiro <vwcruz.stanford.edu> w dniu 27.02.2023, o godz. 09:00:
> 
> Hello Maciej,
> 
> One solution is to load the prmtop and rst7 files into parmed and use the “strip” command to delete the EPW sites from the water molecules you add in the QM region.
> 
> I hope this helps!
> 
> Best,
> 
> Vinícius Wilian D. Cruzeiro, PhD
> Postdoctoral Researcher
> Department of Chemistry
> Stanford University
> Twitter: .vwcruzeiro
> 
>> On Feb 26, 2023, at 10:15 PM, Maciej Spiegel via AMBER <amber.ambermd.org> wrote:
>> 
>> Hello everyone,
>> 
>> I am studying water-mediated hydrogen atom transfer using a QM/MM approach. However, the QM part is unable to converge. It occurred to me that this might be due to the MM EPW dummy atom that is automatically added to the crystallographic water I kept, which I do not include in the QM region. SCC-DFTB is unable to find an integral between it and other atoms, which makes sense.
>> 
>> This is the end of the PDB file I use to generate files for sander (the water is named WAT, it is HETATM, and inserted after the protein):
>> 
>> ========
>> […]
>> ATOM   3971  HA  ALA   265     -24.430 -15.630  -5.376  1.00  0.00           H  
>> ATOM   3972  HB1 ALA   265     -23.133 -15.434  -3.429  1.00  0.00           H  
>> ATOM   3973  HB2 ALA   265     -24.231 -16.311  -2.599  1.00  0.00           H  
>> ATOM   3974  HB3 ALA   265     -23.394 -16.997  -3.820  1.00  0.00           H  
>> TER    3974      ALA   265
>> HETATM 3975  O   WAT   266     -13.426  13.499  -5.935  1.00  0.00           O  
>> HETATM 3976  H1  WAT   266     -12.890  13.976  -6.632  1.00  0.00           H  
>> HETATM 3977  H2  WAT   266     -14.338  13.256  -6.265  1.00  0.00           H  
>> END
>> ========
>> 
>> To solvate the system, I am using the TIP4P-Ew model. However, just after solvation, the crystallographic water in question also "receives" an EPW dummy atom. If I wish to rename the residue as CAQ (crystallographic-aqua), what do I need to do to have it parametrized as a TIP4P-Ew water without the EPW dummy atom? Or maybe there is other solution?
>> 
>> Thank you in advance 
>> --
>> Maciej 
>> _______________________________________________
>> AMBER mailing list
>> AMBER.ambermd.org
>> http://lists.ambermd.org/mailman/listinfo/amber
_______________________________________________
AMBER mailing list
AMBER.ambermd.org
http://lists.ambermd.org/mailman/listinfo/amber
Received on Sun Feb 26 2023 - 23:30:03 PST
Custom Search