How have you create the topology of the ligand??

Please share your topology (.top) file, tip4pew.itp file and briefly mention the steps you have carried out. Also share the complete error log.

The error message "Fatal error: Syntax error - File tip4pew.itp, line 5 Last line read: '[ moleculetype ]' Invalid order for directive moleculetype?" suggests that there is a syntax error in the tip4pew.itp file at line 5, specifically related to the "moleculetype" directive. This error typically occurs when the order of the directives in the file is incorrect or if there is a missing or misplaced directive.

The error message "Fatal error: Syntax error - File tip4pew.itp, line 5 Last line read: '[ moleculetype ]' Invalid order for directive moleculetype?" suggests that there is a syntax error in the tip4pew.itp file at line 5, specifically related to the "moleculetype" directive. This error typically occurs when the order of the directives in the file is incorrect or if there is a missing or misplaced directive.

To resolve this error, you can take the following steps:

- Open the tip4pew.itp file: Locate the tip4pew.itp file using a text editor and navigate to line 5.

- Check the directive order: Verify the order of the directives in the file, particularly around line 5. The "moleculetype" directive should be placed in the correct order within the file. Typically, the order of the directives in a topology file follows a specific structure.

- Ensure correct syntax: Double-check that the "moleculetype" directive is written correctly, including any necessary keywords or parameters. The syntax for the "moleculetype" directive should be in the proper format.

- Check for missing or misplaced directives: Review the surrounding lines and ensure that there are no missing or misplaced directives. Each directive should be properly formatted and placed in the correct order.

- Save the changes: Once you have made any necessary corrections to the tip4pew.itp file, save the changes.

- Retry the simulation: Rerun the simulation using the corrected tip4pew.itp file.