Recent Posts

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91
General / Re: How to run the Gibbs ensemble MC simulation of 3 boxes
« Last post by David Dubbeldam on November 03, 2021, 08:43:14 AM »
It would require reading the code and understanding the flow of the code.
In general "monte_carlo.c" is the start-point for Monte Carlo. It setups the systems and selection of moves etc.
The MC-moves themselves are in "mc_moves.c" which makes use of the routines to compute the energies in the various files like "framework_energy.c", "inter_energy.c", and "internal_energy.c".
92
General / Re: Use RestartInitial’ to re-compute VTK file
« Last post by David Dubbeldam on November 03, 2021, 08:39:00 AM »
Using a Restart-file will save you the equilibration phase. Usually it is best to check your simulation after submitting to make sure the options are set.
In the output, it lists the input-settings so you can check whether options are on or off.
Also, most files are periodically updated so you can see the current results.
93
General / Use RestartInitial’ to re-compute VTK file
« Last post by jimmy on October 25, 2021, 08:41:40 PM »
I did not open the ComputeVTK yes in my input parameter for GCMC simulation but I don't want to redo the whole MC simulation again so after the simulation finished, can I change the directory 'Restart' to ‘RestartInitial’ with ComputeVTK yes input parameter to save time on simulation?
94
General / Re: How to run the Gibbs ensemble MC simulation of 3 boxes
« Last post by imaeda on October 25, 2021, 08:42:56 AM »
Dear Dr. Dubbeldam,

Many thanks for your response.
If I create 3 systems and specify the moves between the boxes of choice, what part of the code do I need to change?

Sincerely,
Imaeda
95
General / Re: Number of molecules in GEMC box
« Last post by sara abbasi on October 17, 2021, 12:29:48 PM »
Dear Dr. Dubbeldum
Thanks a lot for your response. I compared my results with experimental data. The results for liquid density are accurate at all temperatures with the error of 1%, but the results for vapor density are not accurate with the error of 20%. When I compared my results with the results of a paper ,published in 1998, I understood that they could not get the accurate results for vapor density using TraPPE-UA.
What is the reason that vapor density is not achieved? Is not it because of the length of boxes?
SimulationType                MonteCarlo

NumberOfCycles                100000
NumberOfInitializationCycles  10000

RestartFile                   no
ContinueAfterCrash            no
WriteBinaryRestartFileEvery   1000

PrintEvery                    1000
PrintPropertiesEvery          1000

ChargeMethod                  Ewald
EwaldPrecision                1e-5
Forcefield                    TraPPE-UA
CutOffVDW                     14
CutOffChargeCharge            14

Box 0
BoxLengths 30 30 30
BoxAngles 90 90 90
ExternalTemperature 200

Movies                        yes
WriteMoviesEvery              1000

ComputeEnergyHistogram        yes
ComputeNumberOfMoleculesHistogram      yes
ComputeMolecularPressure      yes

Box 1
BoxLengths 30 30 30
BoxAngles 90 90 90
ExternalTemperature 200

Movies                        yes
WriteMoviesEvery              1000

ComputeEnergyHistogram        yes
ComputeNumberOfMoleculesHistogram      yes
ComputeMolecularPressure      yes

GibbsVolumeChangeProbability 0.05

Component 0 MoleculeName             propane
            MoleculeDefinition       TraPPE-UA
            TranslationProbability   0.5
            RotationProbability      0.5
            ReinsertionProbability   0.5
            GibbsSwapProbability     0.5
            CreateNumberOfMolecules  100 100
           
 
96
Command-line utility / How to custom Probe molecule on command-line utility
« Last post by Jamy on October 14, 2021, 09:32:00 AM »
Hi, I'm using a command-line utility to compute the gravimetric surface area of the material.

I'd like to specify the type of probe molecule but I don't know how to do it? Can anyone tell me how can I do this?
97
Simulation algorithms and theory / Re: MC and adsorption capacity
« Last post by YadiJiang on October 14, 2021, 09:09:59 AM »
thank you, sir
98
Input files and parameters / Calculation of adsorbed liquid mixture
« Last post by Fan Honglei on October 14, 2021, 04:11:33 AM »
Hello, Dr. Dubbledam,
     I learned that when calculating the adsorbate in the adsorbed gas phase, when it exceeds its saturated vapor pressure, the adsorption value will become negative.
     I refer to the literature and know that, for example, if I want to calculate the mixture of alcohol and water in the adsorbed liquid phase, I need to set the configuration biased Monte Carlo and calculate the pressure value of the gas-liquid equilibrium of alcohol and water.

My doubts are the following:
1. Is the pressure value when calculating the gas-liquid phase equilibrium (using Aspen software) the pressure value of the input file in Raspa.

2. Is the component ratio of alcohol and water in the input file the liquid phase component ratio in gas-liquid equilibrium? (there is also a gas phase component ratio of alcohol and water in gas-liquid equilibrium)

3. To enable configuration biased Monte Carlo, do I need to write CBMCprobability 1 under the components of adsorbate in the input file? Or do I need to write other parameters?

4. How to solve the problem of using Raspa to calculate the adsorbed liquid phase?

I consulted many literatures about calculating the adsorbed liquid phase, but I was confused about how to operate it in Raspa software.   
99
Simulation algorithms and theory / Re: MC and adsorption capacity
« Last post by David Dubbeldam on October 13, 2021, 08:08:23 PM »
Search for books and literature on grand-canonical ensembles. There are also many books, reviews, articles on the topic of simulation of adsorption.
100
General / Re: Number of molecules in GEMC box
« Last post by David Dubbeldam on October 13, 2021, 08:06:24 PM »
What do you mean wiith "not accurate"? Compared to what? experiment or the result of the TraPPE force field?
Force TraPPE, make sure you use an unshifted potential and tailcorrections.
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