iRASPA cannot display the density map

[John Walker]

Dear:
    I have recently been using MOF materials for methane adsorption, and have attempted to import VTK files generated by RASPA2.0.4 into the IRASPA software. I am only able to generate MOF structure diagrams, but not the methane diagrams. I imported using 'DensityProfile_methane' and 'COMDensityProfile_methane' from the VTK folder, and received the error 'Import failed, Cannot read VTK header (line: 910 file: iraspagui/mainwindow.cpp)'. Importing 'Framework_final.pdb' from the Movies folder does display the molecular structure, which confuses me. How can I produce a methane adsorption density map? I can do it with VisIt.

SimulationType                   MonteCarlo
NumberOfCycles                   30000
NumberOfInitializationCycles     5000
PrintEvery                       1000
ContinueAfterCrash               no
#WriteBinaryRestartFileEvery     1000

ChargeMethod                     Ewald
EwaldPrecision                   1e-6

Ensemble                         NVT
TimeStep                         0.0005

Forcefield                       GenericMOFs

CutOffVDW                        12

RemoveAtomNumberCodeFromLabel    yes

Movies                           yes
WriteMoviesEvery                 1000
RemoveAtomNumberCodeFromLabel    yes         

UseChargesFromCIFFile            yes
Framework                        0
FrameworkName                    HKUST-1
UnitCells                        2 2 2
HeliumVoidFraction               0.39778
ExternalTemperature              298.15
ExternalPressure                 1.0e+06

ComputeDensityProfile3DVTKGrid   yes
WriteDensityProfile3DVTKGridEvery 1000
DensityProfile3DVTKGridPoints    150 150 150
AverageDensityOverUnitCellsVTK   yes
DensityAveragingTypeVTK          FullBox

Component 0        MoleculeName                 methane
                   MoleculeDefinition           TraPPE
                   IdealGasRosenbluthWeight     1.0
                   TranslationProbability   1.0         
                   RotationProbability      1.0       
                   ReinsertionProbability   1.0         
                   ##CBMCProbability          1.0
                   SwapProbability          1.0         
                   CreateNumberOfMolecules  0

[Lingxiao Qin]

I have tried your input file, and both the 'DensityProfile_methane.vtk' and 'COMDensityProfile_methane.vtk' output files can be successfully imported into iRASPA. I suggest checking the versions of RASPA and iRASPA that you have installed. The latest version of RASPA is v2.0.47, so I doubt whether you really installed RASPA v2.0.4 (released in 2016) or it is just a typo. The VTK files generated by such an old version of RASPA might not be readable by iRASPA. I am not sure of the exact version of RASPA I am using, but it was at least released after 2022. I downloaded iRASPA from the Windows store, which was released in 2018. By the way, the lines

Code Select Expand

Ensemble NVT
TimeStep 0.0005 in your input file seem unusual. From my understanding, these options are used for molecular dynamics simulations and should not be used in a Grand Canonical Monte Carlo simulation, so I commented these two lines when testing your input file.