Recent Posts

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General / Re: Irreproducible Partial Charges uing Qeq method
« Last post by David Dubbeldam on June 08, 2021, 02:39:04 PM »
Yes, all Qeq are differently implemented. The code in RASPA is based on the method of Wilmer and Snurr.
https://pubs.acs.org/doi/10.1021/jz3008485
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General / Re: parameter input
« Last post by David Dubbeldam on June 08, 2021, 02:36:34 PM »
The 'pseudo_atoms.def' contains predefined atoms, and this is often the way to go for molecules.
This especially important for united atom types etc.

For frameworks, read from a CIF file, there is always an element defined (_atom_site_type_symbol), and the type (_atom_site_label) is automatically added when found. The mass is a lookup from a database in 'src/scattering_factors.c'.
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Input files and parameters / Re: Density histograms
« Last post by David Dubbeldam on June 08, 2021, 02:28:59 PM »
This function writes out a VTK-file, a 3D histograms of the density. See the examples on Visualization.
You could also read this file yourself.
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Input files and parameters / Re: Use of dreiding force field
« Last post by David Dubbeldam on June 08, 2021, 02:26:43 PM »
The DREIDING force field uses specific functional forms and parameters. You can look these up and use (most of) these in RASPA.
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Input files and parameters / Re: Error - mixed gas adsorption
« Last post by David Dubbeldam on June 08, 2021, 02:11:36 PM »
Input looks, at first sight, okay to me. Remove as much as possible, i.e. component 1-3 etc, and check if it works. Then from add the components one by one to see where it goes wrong.
In general, change stuff in small steps, otherwise it is harder to debug.
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I don't think this is currently possible. The implementation of the CBMC algorithm used for the insertion is the limitation here.
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General / Irreproducible Partial Charges uing Qeq method
« Last post by AHF on June 03, 2021, 10:35:53 AM »
Hello RASPA community,

I am trying to reproduce partial charges of BEA zeolite using the Qeq method. My reference is Table 2 of the following paper by Wolffisa et al:  https://www.sciencedirect.com/science/article/abs/pii/S1387181118305614

In this paper, they have used Qeq method as implemented in GULP, although I am using RASPA for this purpose. I am using the exact same structure, however I still get results that are very different from what is reported in this paper. I have also tested different oxidation states but still no success.

I was wondering if there is any other parameters to tune in RASPA in order to reproduce the above partial charges? Could the observed discrepancy be simply due to different implementation of Qeq method in GULP and RASPA?

Any help will be greatly appreciated.
Best regards,
AHF
 
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General / parameter input
« Last post by sfritzsche on May 31, 2021, 05:21:54 PM »
Dear RASPA experts,
I am doing MD and MC for more than 35 years and now I want to try to use RASPA instead of own
software. It is a great software. But, I don't want to use it a as black box.
My question: In the output file of an example calculation with ZIF-8 I found the mass for Zn to be
65.408728088. From which input file RASPA has taken it?
The pseudoatoms.def  files seem to be only for guest molecules and the cif for the lattice
does not contain masses.
A search for the string "65.4087" throughout the RASPA2 master directory and all subdirectories
found this string only in the output files of examples.

Many thanks for your help,

Siegfried Fritzsche
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Thanks for your reply!

Best wishes,
Yang
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No, the pressure is indeed not used in this example.
I will remove the pressure line in the example.
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