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#31

Input files and parameters / Ethylene with TraPPe UA2 probl...

Last post by CheMiNuB - March 08, 2025, 10:38:21 PM

Im trying to simulate the adsorption of c2h4 on mofs  using different models
only with TraPPe_UA2 i keep getting the error

Simulation finished,  1 warnings
WARNING: ENERGY DRIFT (INTERNAL CONSISTENCY ERROR IN THE CODE), THE SIMULATION RESULTS ARE WRONG!!

Here's my Model

# critical constants: Temperature [T], Pressure [Pa], and Acentric factor [-]
282.4
5032000.0
0.085
# Number Of Atoms
4
# Number Of Groups
1
# Alkane-group
Rigid
# number of atoms
4
# atomic positions
0 CH2_sp2 0.0   0.0  0.0
1 CH2_sp2 1.70  0.0  0.0
2 D       0.85  0.65 0.0
3 D       0.85 -0.65 0.0
# Chiral centers Bond  BondDipoles Bend  UrayBradley InvBend  Torsion Imp. Torsion Bond/Bond Stretch/Bend Bend/Bend Stretch/Torsion Bend/Torsion IntraVDW IntraCoulomb
               0    2            0    0            0       0        0            0         0            0         0               0            0        0            0
# Bond stretch: atom n1-n2, type, parameters
0 1 RIGID_BOND
2 3 RIGID_BOND
# Number of config moves
0

Anybody has any ideas ?

#32

Input files and parameters / I need help running MC simulat...

Last post by Ismail - March 04, 2025, 03:18:04 PM

Dear Professors,
I am a beginner with RASPA. And i am running a project on atmospheric water adsorption using COFs. I am facing errors of PseudoAtomNumber. I have tried all my best to resolve this issue but i am not getting it. Please help.
My files are attached for your reference.
Thank you and i look forward to your suggestions

#33

General / Re: Question about raspa

Last post by David Dubbeldam - February 26, 2025, 03:52:26 PM

Yes, rigid molecules are supported. Also, per component you can block or allow certain regions for insertion/deletion.

#34

General / Re: No general mixing rule but...

Last post by David Dubbeldam - February 26, 2025, 03:47:11 PM

You have not specified the interactions for C-O C-Ca C-CH4_sp3 Ca-C Ca-O Ca-CH4_sp3 CH4_sp3-C CH4_sp3-O CH4_sp3-C CH4_sp3-O CH4_sp3-C CH4_sp3-O CH4_sp3-C CH4_sp3-C etc. Generally you will need to define these in the 'force_field_mixing_rules.def' file, using a self-interaction and a mixing rule to get the cross-interactions.

#35

Input files and parameters / Re: No VDW interaction

Last post by Jacker - February 18, 2025, 12:02:15 PM

Have you addressed the above issues? I am experiencing the same problem, please give me some suggestions on how to solve this problem.
I am using RASPA2 to simulate the adsorption of CH4 on Aragonite (CaCO3) using UFF-Dreiding force field and methane molecule, and the results keep showing THERE ARE ATOM-PAIRS WITH NO VDW INTERACTION C-O C-Ca C-CH4_sp3 Ca-C Ca-O Ca-CH4_sp3 CH4_sp3-C CH4_sp3-O CH4_sp3-C CH4_sp3-O CH4_sp3-C CH4_sp3-O CH4_sp3-C CH4_sp3-C (maximum interactions shown).sp3 O-C O-Ca O-CH4_sp3 Ca-C Ca-O Ca-CH4_sp3 CH4_sp3-C CH4_sp3-O CH4_sp3-Ca (maximum 50 interactions shown); I set to general mixing rule for Lennard-Jones: Lorentz-Berthelot, but the result is "No general mixing rule: all cross term specified individualy",I have not found the reason for this, how to remove this warning, please advise me, thank you!

#36

General / No general mixing rule but I s...

Last post by Jacker - February 16, 2025, 03:51:12 PM

Hi Dr Dubbeldam:

I am a new user to the RASPA2.0.
I have run the examples from the RASPA2.0 manual and my own tests, warning of atom-pairs with no VDW interactions have been found in the output files.

I am using RASPA2 to simulate the adsorption of CH4 on Aragonite (CaCO3) using UFF-Dreiding force field and methane molecule, and the results keep showing THERE ARE ATOM-PAIRS WITH NO VDW INTERACTION C-O C-Ca C-CH4_sp3 Ca-C Ca-O Ca-CH4_sp3 CH4_sp3-C CH4_sp3-O CH4_sp3-C CH4_sp3-O CH4_sp3-C CH4_sp3-O CH4_sp3-C CH4_sp3-C (maximum interactions shown).sp3 O-C O-Ca O-CH4_sp3 Ca-C Ca-O Ca-CH4_sp3 CH4_sp3-C CH4_sp3-O CH4_sp3-Ca (maximum 50 interactions shown); I set to general mixing rule for Lennard-Jones: Lorentz-Berthelot, but the result is "No general mixing rule: all cross term specified individualy",I have not found the reason for this, how to remove this warning, please advise me, thank you!

Best

Jacker

#37

General / Question about raspa

Last post by antoine - February 10, 2025, 02:16:11 PM

Hello everyone, I hope you are doing well. I want to start using RASPA for GCMC simulations and would like to know if RASPA supports defining specific regions for insertion, deletion, and Monte Carlo moves. Additionally, does it support rigid molecules, such as the SPC water model in my case?

#38

General / Limit on the number of atoms

Last post by cvm14 - February 10, 2025, 05:10:03 AM

Dear Professor,

I have a system with more than 100 atoms, including heavy atoms and a transition metal, along with C, H, and O. I want to perform density estimation using an NPT ensemble in RASPA. When I attempted this calculation, it returned no output directories or error messages. I wonder if RASPA allows a certain number of atoms during execution, as I could run a molecule with the same elements as above but with less than 100 atoms. Can you please direct me on how to tackle this issue?

#39

General / Re: Seeking Advice: RASPA3 vs ...

Last post by David Dubbeldam - January 29, 2025, 10:23:51 PM

There are packages for linux, including centos 7 at:
https://github.com/iRASPA/RASPA3/releases

#40

Visualization / Re: Adsorption density distrib...

Last post by David Dubbeldam - January 29, 2025, 07:31:14 PM

You probably used "surface"-rendering. With "volume-rendering" you can get more of a color-gradient.
Bonding is controlled by a general rule, also employed by VMD: The radius < (covalent radius of atom1 + atom2 + 0.56).