From: Ashar Malik (
Date: Sat Jul 16 2022 - 08:22:11 CDT

Are you a windows user?

Does the program have permission to write files to disk where you are
trying to write?

The Config file might not have been written to disk if you don’t have
permission to write to disk.

If you are indeed a windows user, starting the program in admin more or
choosing a different working directory (where you have permission to write)
will fix this.

Hope this helps.

On Sat, 16 Jul 2022 at 7:10 PM, Kartik Tulsian <>

> I Have been trying to use the NAMDenergy plugin in vmd to calculate Vdw
> and electrostatic energies of my simulation, however upon running the
> plugin i receive the following error.
> FATAL ERROR: Unable to access config file namd-temp.namd
> FATAL ERROR: Unable to access config file namd-temp.namd
> while executing
> "exec $namdcmd ${jobname}-temp.namd > ${jobname}-temp.log"
> (procedure "namdrun" line 56)
> invoked from within
> "namdrun"
> (procedure "namdmain" line 76)
> invoked from within
> "namdmain"
> (in namespace inscope "::namdEnergy" script line 19)
> invoked from within
> "::namespace inscope ::namdEnergy {
> mol top $currentMol
> variable sel1
> variable sel2
> variable nsel
> set energy ""
> set..."
> invoked from within
> ".namdenergy.gobutton invoke"
> ("uplevel" body line 1)
> invoked from within
> "uplevel #0 [list $w invoke]"
> (procedure "tk::ButtonUp" line 24)
> invoked from within
> "tk::ButtonUp .namdenergy.gobutton"
> (command bound to event)
> the temporary file it is talking about is supposed to be generated by vmd
> to store temp data so i am really confused as to what to do about this error