No VDW interaction

[CharleneZ]

I am getting an error regarding no VDW interaction for some molecules. I have defined the appropriate molecules to the force_field_mixing_rules to the file, but I still get the error. Is there anything immediately wrong with the file below? I am not sure how to erase this issue. When running the simulation I get the error below:

WARNING: THERE ARE ATOM-PAIRS WITH NO VDW INTERACTION CH4-C1 CH4-C2 CH4-C3 CH4-C4 C1-CH4 C1-C2 C1-C3 C1-C4 C2-CH4 C2-C1 C2-C3 C2-C4 C3-CH4 C3-C1 C3-C2 C3-C4 C4-CH4 C4-C1 C4-C2 C4-C3  (maximum 50 interactions shown)



My force_field_mixing_rules.def file is below:

# general rule for shifted vs truncated
shifted
# general rule tailcorrections
no
# number of defined interactions
9
# type interaction, parameters.    IMPORTANT: define shortest matches first, so that more specific ones overwrites these
C1             lennard-jones    47.0      3.74
C2             lennard-jones    47.86     3.47
C3             lennard-jones    47.86     3.47
C4             lennard-jones    47.86     3.47
CH4            lennard-jones    158.5     3.72       
CH3            lennard-jones    108.0     3.76       
CH2            lennard-jones    56.0      3.96       
CH             lennard-jones    17.0      4.67       
C              lennard-jones     0.8      6.38     

# general mixing rule for Lennard-Jones
Lorentz-Berthelot

Any help is appreciated!

[Jacker]

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!

[justyna]

Hi,

there is an empty line between the last atom and #general mixing rules. This is very often causing errors. To avoid it remove the empty line like so:

...
C              lennard-jones     0.8      6.38     
# general mixing rule for Lennard-Jones