TIP3P water model in MD


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Dear all,
Since the Amber force field has been parametrized mainly for the TIP3P water model, I'm trying to use it instead of the default SPC/E. I took the parameters from the standard Amber .in files, translated them into NWChem .par format, so that the stretching and bending parameters for OW and HW atoms correspond to the TIP3P model. However, after running the simulation, bonds and angles are still 1.0 A and 109 deg, respectively. The only files listed in .nwchmrc are amber.par file with TIP3P parameters for HW and OW, HOH.frg and spce.rst, but I didn't find any parameters in the last one, so i left it unmodified.
Can anyone tell me what I am doing wrong? Thank you.

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TIP3P water model
Dear Omen,

I am a fresh man in MD simulation. I wish get some help from you. Do you solve the problem for TIP3P water model? If you get the correct file for TIP3P water model, please give me these file, I am very appreciate it. And also could you tell me which water model suitable to which condition according your experience. Thank you very much.

Jingbo

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I assume you prepared "TIP3P.sgm" or "TIP3P.frg" with the segment definition for TIP3P water using the appropriate atom types. If you haven't, this would be easy to do starting from the available "spce.sgm".
Once you have that, using this model is enforced by putting in the prepare input deck to generate the topology file the directive:

"solvent model TIP3P"


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