Messages

[pairs]

That is not implemented. Usually, these should be the same, since you are looping of interaction-pairs.

Are you using the official version from https://github.com/iraspa/raspa2 ?
Versions by other people (not us) via python-use reportedly can show this issue.

If so, check that it actually writes output by running MUCH shorter (10 cycles) and check all the output.
In the output-file it should say whether it computes MSD or not.

This is on the TODO list.

In the gallery, then primitives, then IRMOF-1, you can see such an example.

Note that if you do not use an initialization phase, the bias is measured while the adsorption is going up.
Also note that you are comparing CBCMC vs CFCMC. I would guess that CB/CFCMC would probably not plateau like that during initialization.

"I managed to make and use the grid, but my adsorption is way too high for my system of LTA4A and water.", way too high compared to what?
Did you compare with and without using grids?

These are old files, 'RASPA2/examples/Visualization' will be removed soon. These files you do not need to generate, you can directly use volume-rendering in iRASPA to visualize the framework.
Only for density volume-renderings do you need to regenerate the 3D VTK-densities using the latest version of RASPA.

The values are not the same. Excess is slightly smaller.

In the limit of low pressure, excess and absolute adsorption become equal. They start to deviate at high pressures.

Make sure your 'propylene' definition contains the proper critical temperature, pressure, and eccentric factor such that the Peng-Robinson Equation of State can compute the conversion properly.

You could email Reza Rahbari and ask him how he did it. But note there is no single convention and the results will differ depending on what assumptions and choices you make.

Partition functions are not part of RASPA but are input. So you will need to compute them. There are many different ways of doing that, and they do differ in results.

For some pointers:
https://homepage.tudelft.nl/v9k6y/thesis-Rahbari.pdf
Page 262 and following, and see Table  A5.

Pressure is not well-defined if you use a fixed framework. Even for a flexible framework, keep in mind that for solids pressures are in the orders of Gpa for a small structural difference and hence pressure for solids fluctuate a lot more than liquids, which fluctuate more than gases.

It is always a good idea to check you solution for consistency and whether the result is correct.
So yes, in general you would take at least two different approaches to confirm you get the correct values.

It is very customary to write scripts precisely for the reason you mention. Different software use different input, and you often need to convert.
It pays off to write scripts to take care of that.

For classical simulations and classical simulations software, you always need to define the same things:
1) the positions of all the atoms that are present at the start of the simulation, like the framework.
2) the types of atoms
3) the force field, including charges, VDW, and all the bond, bend, torsions for flexible adsorbates and flexible frameworks.
4) the simulation input parameters, like pressure, temperatures, and MC moves etc.
......

There is no way around that issue and is the nature of classical simulations. Most people working with RASPA, Towhee, GULP, DLPOLY, LAMMPS struggle with this simulation-theory side. But there are many good books on this topic.
RASPA is not the most difficult input, for example, you can just list the amount of molecules, and the code generates the positions atomically. In LAMMPS, DLPOLY etc you first need to create all the initial positions 'by hand'.

You have interactions pairs that are undefined. To get rid of this warning, define the interactions (if you really meant no interactions, then use type 'none').
Also, apparently there is a net charge, which might be small but non-zero. Check whether the value is small enough.