Hello all!
I am a fairly new EMC user and have been using the package to build a polyamide acid system that contains imide functional groups using the PCFF force field:
However, an error occured as follow:
I saw someone raise similar questions, but still have trouble to modify pcff_template.dat for me. SMILES:NC(=O)c6cc(C(=O)Nc5ccc(Oc4ccc(NC(=O)c3cc(C(=O)Nc2ccc(Oc1ccccc1)cc2)c(C(=O)O)cc3C(=O)O)cc4)cc5)c(C(=O)O)cc6C(=O)O
Sorry, Image is not clear and the specific text as follows:
Warning: increment pair {c_1, na} not found.
Error: core/script/field/entry, c:641 Script FieldEntryApply
Missing force field parameters.
The warning you are experiencing is due to designation of bond increments: a mechanism through which partial charges are assigned. By default, EMC throws an error, when any of the bond increment parameters are missing. The PCFF force field and its format find its origin in the Materials Studio package. This package assumes that bond increment contributions are zero when missing. You can tell EMC to behave in a similar manner by setting the following in your .esh script:
ITEM OPTIONS
field_increment warn
ITEM END
This way, EMC will still throw a warning, when the increment is missing. If you do not want to be warned, you can also opt for ignore instead of warn, in which case no message is generated when bond increment parameters are missing. In both cases no contribution is added to the partial charge.
Im having a similar issue when creating CO2. I tried putting field_increment warn, but it still pops up an error. I attach my input esh file and the error.
It seems to me, that – after checking the pcff_templates.dat rules file – PCFF has no parameters for carbon dioxide. Setting field_increments to warn will not help you there. You will have to add the missing parameters to the force field files to get carbon dioxide to work. Please note that the PCFF files provided by EMC are the original files.
