Recent posts

#21

General / Molfraction problem in adsorpt...

Last post by Sirius Black - June 16, 2025, 01:46:33 PM

Dear all,

When I compared the Raspa manual for example practice, I attempted to reproduce the adsorption of CO2/CH4 (1:3) mixed gas in IRMOF-1. The manual's output correctly displayed the MolFraction of 0.25 and 0.75 for both, but the output I ran had a MolFraction of 0.5 for both. Although I had correctly set the MolFractrion keyword in the simulation.input file and no matter how I adjusted the value of Molfraction, both components were initialized to a MolFraction of 0.5 for simulation in the run results

I am using conda-forge to install Raspa2. Is there a problem with the software I am installing?

I am attaching my input file and running results below.(For the sake of convenience, I will take screenshots of the questions section to display.)

If anyone can answer my doubts, I would be extremely grateful.

#22

General / How to obtain Henry coefficien...

Last post by CaiXT1999 - June 16, 2025, 03:31:57 AM

Dear All,

I noticed that RASPA3 does not output the Henry coefficient or the isosteric heat directly, unlike RASPA2.

Do I need to manually compute the Henry constant from the chemical potential?

Is there currently a standard way in RASPA3 to get the adsorption enthalpy at infinite dilution?

Any guidance or examples would be greatly appreciated. Thanks!

Here's my json input file:
{
  "SimulationType" : "MonteCarlo",
  "NumberOfCycles" : 100000,
  "NumberOfInitializationCycles" : 0,
  "PrintEvery" : 1000,

  "ForceField" : ".",
 
  "Systems" : [
    {
      "Type" : "Framework",
      "Name" : "UiO-66",
      "NumberOfUnitCells" : [2, 2, 2],
      "ExternalTemperature" : 298.15,
      "ExternalPressure": 1e5,
      "ChargeMethod" : "Ewald",
      "CutOff" : 14.0,
      "UseChargesFrom": "CIF_File"
    }
  ],

  "Components" : [
    {
      "Name" : "SPCE",
      "WidomProbability" : 1.0,
      "CreateNumberOfMolecules" : 0
    }
  ]
}

#23

General / Simulation about Helium void f...

Last post by Kimchen - June 11, 2025, 12:16:51 PM

Dear All,

I try to run a helium void fraction simulation on Raspa3, it seems working, but i can not find any info about the result in the output files.
Does anyone knows about this issue?

#24

General / Heat of adsorption calculation...

Last post by SEB - June 10, 2025, 05:18:41 PM

Hi everyone,

After upgrading to the newest version of RASPA 2 version 2.0.50 from 2.0.37 I am getting issue computing heat (enthalpy) of adsorption using GCMC. It is printing NaN instead of the computed value.

The system is composed of a rigid framework (zeolite) + mobile cations + adsorbate.

The GCMC is carried out as a restart simulation (necessary to place cations in specific positions).

Has anyone ran into the same issue? Any suggestions would be appreciated.

Thanks.

#25

General / Heat of adsorption calculation...

Last post by SEB - June 10, 2025, 05:16:21 PM

Hi everyone,

After upgrading to the newest version of RASPA 2 version 2.0.50 from 2.0.37 I am getting issue computing heat (enthalpy) of adsorption using GCMC. It is printing NaN instead of the computed value.

The system is composed of a rigid framework (zeolite) + mobile cations + adsorbate.

The GCMC is carried out as a restart simulation (necessary to place cations in specific positions).

Has anyone ran into the same issue? Any suggestions would be appreciated.

Thanks.

#26

General / Re: Segmentation Fault When Cr...

Last post by had-sham - June 05, 2025, 12:15:49 PM

Hi everyone,
Has anyone encountered this issue before? I'd appreciate any help or advice.
Thank you

#27

Input files and parameters / Error: Unknown input 'WriteBin...

Last post by Kimchen - May 29, 2025, 10:23:12 AM

Hi Guys, i want to create a input file which contains WriteBinaryRestartFileEvery, but when i try to run the simulation, this error comes out. i read the manual, it should have this function in the simulation, does anyone knows what is the reason for that?
Here is my input file:
{
    "SimulationType": "MonteCarlo",
    "NumberOfCycles": 4000,
    "NumberOfInitializationCycles": 1000,
    "PrintEvery": 100,
    "Forcefield": ".",
    "WriteBinaryRestartFileEvery": 100,
    "Systems": [
        {
            "Type": "Framework",

#28

General / Segmentation Fault When Creati...

Last post by had-sham - May 28, 2025, 11:52:20 PM

Hi everyone,

I'm encountering a "Segmentation fault (core dumped)" error every time I try to generate grids. Has anyone faced a similar issue, or does anyone know how I can resolve this?

Thanks in advance for your help!

#29

General / Status of Flexibility

Last post by petersbk - May 28, 2025, 07:20:04 PM

The README says that flexible molecules (and frameworks) are on the ToDo list, but I noticed several ...flexible...cpp files. What is the status and/or expected timeline or prioritization for inclusion of flexibility? Of course, I'm not expecting promises! I have a project that requires flexibility (molecules most important) and RASPA3 just looks so promising, I'd love to use it. Thanks.

#30

Breakthrough / Breakthrough curve time overes...

Last post by AntonioDouglas - May 27, 2025, 05:18:42 AM

Hi, everyone.
I am trying to get the breakthrough curve for CO2/H2 mixture in a MOF.
I read and followed the instructions present in "S. Sharma, S. Balestra, R. Baur, U. Agarwal, E. Zuidema, M. Rigutto, S. Calero, T.J.H. Vlugt, and D. Dubbeldam, Molecular Simulation Journal, 49(9), 2023". And everything seems right, however, the breakthrough curve time appears to be overestimated. I saw in different papers (theoretical studies GCMC) that CO2 usually start under 50 (Time, t/[min.]) or under 600 (Dimensionless time)(experimental studies), but my results (with isotherms obtained with GCMC/RASPA and fitted with RUPTURA) start around 400 (Time, t/[min.]) or close to 1700 (Dimensionless time). 
I already used several approaches combined: SIAST, IAST, EI, Langmuir, Langmuir-Freundlich, the number of isotherm sites, changes in column entrance velocity, and more. But the results that I get are weird. Curiously, when I tried repeating the examples provided in GitHub, I was able to get the same good results.
I am new in the RUPTURA use, so if someone has some tips, I would appreciate it.
(Attached is one between 21 tries done until now)