Open bjkreitz opened 3 months ago
WARNING:root:Initial mole fractions do not sum to one; normalizing. WARNING:root:Initial mole fractions do not sum to one; normalizing. WARNING:root:Initial mole fractions do not sum to one; normalizing. ⚠️ One or more regression tests failed. Please download the failed results and run the tests locally or check the log to see why.
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WARNING:root:Initial mole fractions do not sum to one; normalizing. WARNING:root:Initial mole fractions do not sum to one; normalizing. WARNING:root:Initial mole fractions do not sum to one; normalizing. ⚠️ One or more regression tests failed. Please download the failed results and run the tests locally or check the log to see why.
beep boop this comment was written by a bot :robot:
Motivation or Problem
There are a couple of species that we currently cannot handle in RMG when generating mechanisms for heterogeneously catalyzed reactions, because we have no way to represent them in RMG. One of these species is bidentate formate OC(H)O.
This adsorbate is a bidentate species, where both oxygen adatoms have the same distance to the surface. Formate is an important intermediate in many reactions mechanisms, like methanation or methanol synthesis. The only way to draw a Lewis structure for this species is to assume a resonance structure, where one of the oxygens doesn't have a bond to the surface. It is necessary to tell RMG that this is a bidentate species and that both oxygen atoms are coordinated with the surface atoms. There is also a stable monodentate formate species and our Lewis structure for the bidentate needs to be different from the monodentate.
Description of Changes
I adjusted RMG to handle this structure (and similar adsorbates) by introducing a vdW bond between the oxygen and the surface atom. This tells RMG that the oxygen and the surface atom are connected.
These vdW bonds occur only in multidentate adsorbates that have another covalent bond with the surface. If a reaction recipe leads to a species with only vdW bonds to the surface, RMG still removes those and forms a physisorbed structure.
Testing
I was able to generate a mechanism with the bidentate formate and it can also participate in reactions, when I provide new reaction families that can form and break this bond.
Reviewer Tips
This is still a work in progress and requires further updates. I'm just looking for initial thoughts on whether this approach is the right one to address this issue.