Tina Düren: Research Section
Program to calculate the excess amount adsorbed
Calculating the excess amount adsorbed
Running the program for other systems
The Program as it is provided here, can be used to calculate the excess amount adsorbed for methane in IRMOF1. It is easy to extent
the Program to handle other fluids / gases and MOFs.
Changing the adsorbent
The subroutine adsorbent_properties_UFF.f90 contains a database for adsorbents. Three properties of the adsorbent need to be specified:
- the mass of the unit cell in g / mol
- the crystal density in g / cm3
- the pore volume in A3
The first two properties are used to convert the units from molecules / uc to (currently) mol / g and cm3 / cm3. We normally calculate the pore volume from the second virial coefficient (for details see AL MYERS and PA Monson "Adsorption in porous materials at high pressure: Theory and experiment", Langmuir 18, 10261 (2002)). This method is based on calculating the potential energy between a single helium molecule and the MOF framework. The value therefore depends on the force field used.
Adding more fluid molecules
The subroutine fluid_properties.f90 contains a database for fluid molecules which contains the parameters necessary for the Peng Robinson equation of state. You can find these properties in thermodynamic books such as Reid, Prausnitz, Poling "The properties of gases and liquids".
- the accentric factor
- the critcial temperature in K
- the critical pressure in Pa
Don't forget to recompile the program if you added something new!