From: Sarthak Mohanty (sarthakmohanty997_at_gmail.com)
Date: Fri Dec 16 2022 - 11:59:06 CST

Hello VMD users!

I am trying to merge two PSF files and two PDB files together into a single
PSF file and PDB file respectively. To do this I am using the following TCL
script that I found online:

#!/usr/bin/tcl

package require psfgen
resetpsf

readpsf 1stp_protein_autopsf.psf ##enter filename of the protein's PSF
readpsf 1stp_BTN.psf ##enter filename of the ligand's PSF

coordpdb 1stp_protein_autopsf.pdb ##enter filename of the
protein's PDB
coordpdb 1stp_BTN_charmm.pdb ##enter filename of the
ligand's PDB

writepsf 1stp_final.psf
writepdb 1stp_final.pdb
quit

However, running this script in VMD presents the following error:
coordinate file arguments should be "[pdb|namdbin] <filename>"
MOLECULE DESTROYED BY FATAL ERROR! Use resetpsf to start over.

I am new to VMD and TCL scripting which is why I need help solving this
problem. Any and all help will be much appreciated.

Thank you
-Sarthak Mohanty