| 5:24:18 AM PDT - Thu, Oct 18th 2012 |
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Unfortunately, I can not reproduce articles models 2 and 3 in NWChem too.
I have the impression that there is a problem with the units of “weight”.
Both the article and the documentation of NWChem says that it is the atomic units.
However, if you increase the hyperbolic constant in 50 times, and harmonic constant in 30 times, the results agree with the article.
Similarly, if the increase is 30 times the constant of my implementation (model 1), the results agree with the article.
So, I think that my (model 1) code is working properly, but it is necessary to deal with the input constants in all models.
The input file for methanol can be found here. Here are also modified sources. No binaries.
I allow the user defined target charges not only for harmonic functions, but for the hyperbolic too.
Quote:Bert Oct 17th 7:44 pmBefore you start coding it is key to understand the code, how it solves the equations you are interested in. You should not make guesses. What I recommend you do is to take the RESP paper and match up the coded equations to those in the paper. This will give you an understanding of what the code does and how it relates to the paper. Using the "q0" parameter should give you equation 1, at least when I match up the code. The b variable seems to match up with your b-variable in your equation 3.
I am not going to open files with binaries because of security issues. Have you done some tests that allow you to compare to the published data? This will allow you to test for correctness.
Bert |