"FlexibleDefinition" option is mandatory?

[Junran Lu]

Hi, everyone, when I try to simulation the N2 adsorption in flexible Metal-Organic Frameworks，in the simulation.input file, it is mandatory to use the "FrameworkDefinitions" ? Could I just use the "FlexibleFramework" option to tell the RASAP code the framework is flexible? if the "FrameworkDefinitions" is mandatory, and how could I edit or generate the file?

[David Dubbeldam]

Checkout the example: examples/Advanced/Adsorption_of_CO2_in_Flexible_IRMOF-1_Fixed_Volume.
For a flexible framework  you need to specify:
(1) FlexibleFramework yes
(2) FrameworkDefinitions Dubbeldam2007FlexibleIRMOF-1
The first says that you treat the framework as flexible, the second specifies the force field file used.
For this example it is listed in 'framework/Dubbeldam2007FlexibleIRMOF-1/framework.def' and on 'make install' copied to '~/RASPA/simulations/share/raspa/framework/Dubbeldam2007FlexibleIRMOF-1/'
To use your own force-field you can
(1) copy this file in your current directory, so it will be read first.
(2) modify the force field for your specific case.

[Junran Lu]

Hi，David Professor, thanks for your reply.
However, to modify or generate the specific case, namely "FrameworkDefinitions" is not an easy thing, is there a program or code to generate the framework.def ?

[David Dubbeldam]

I am not aware of such a program. Most papers that publish forcefields list all the potentials and parameters in tables, and you need to input them into the file and check it carefully.

[Junran Lu]

Hi, David Professor:
Thanks for your suggestions.
I will retrieve the related papers and have a try.