Recent posts

#1

General / Matrix Inversion, Gauss-Jordan...

Last post by Auri - Today at 11:14:23 AM

Hi everyone
I've been stuck here for a month. I want to add ionic liquid to MOF, but after the simulation, it shows: Matrix Inversion, Gauss-Jordan: Singular Matrix.
I tried to modify the molecular definition file and L-J parameters, and also made sure the system is electrically neutral, but the Singular Matrix still appears. I checked the output file and found that the enthalpy is also NaN.
Has anyone encountered this problem?
I'd appreciate any help or advice.
Thanks.

#2

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.

#3

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
    }
  ]
}

#4

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?

#5

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.

#6

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.

#7

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

#8

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",

#9

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!

#10

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.