Charge Neutrality Error in Potential Calculation

GULP
1

I am trying to find Interatomic potential (Buckingham potential) for hexagonal phase of NaYF₄ in GULP 6.2 (running via Cygwin on Windows 11).

I am encountering an error stating that the unit cell is not charge neutral.

What could be causing this discrepancy? Are there specific aspects of charge assignment, potential parameters, or computational settings that might lead to this issue in GULP?

Would using the qok keyword be appropriate in this case?

I have attached snippet of input file.

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image612×847 9.3 KB

I have attached snippet of the error message.
image

Any guidance would be greatly appreciated.

Best regards,
Aravind

2

The answer to your problem is on page 140 of the manual (version 6.2) where how to input a structure is introduced (also look up the concept of a special position in crystallography). NB: Using qok would be pointless here - the problem is that you have the wrong stoichiometry in your structure, so enable a calculation to run on the wrong structure is not the correct approach.