From: Bassam Haddad (
Date: Sat Sep 18 2021 - 11:02:25 CDT

Hello again,

In an attempt to trouble-shoot my previous problems, I performed the ffTK
tutorial using the .psf/.pdb/.par from the tutorial files. The charge
optimization step worked, which tells me that there is an issue with the
way that CHARMM-GUI generated the .psf of my ligand.

I did however run into another problem, however, while running the tutorial
files (ETOH). When I went to run the bond and angle optimization, ORCA
threw an error saying it needed "initial.hess" as an input and could not
find it. "initial.hess" is not generated when using the "Write QM Inputs"
function in the ffTK GUI. Where can we find/build initial.hess for our own

Thank you for your time!


On Mon, Sep 13, 2021 at 12:38 PM Bassam Haddad <> wrote:

> Hello All,
> I am currently trying to parameterize a small molecule using fftk on
> vmd_1.4a51, with ORCA, and I ran into an error preceding charge
> optimization:
> `ERROR) No molecules loaded.mol addfile operates on one molecule only`
> Though the .psf and .pdb are loaded. All ORCA inputs were generated in
> ffTK, and orca ran without error. I have seen this error pop-up on the mailing
> list before
> <>however
> it appears to be an unrelated issue, as I am not using Gaussian, and don't
> appear to have errors from ORCA. I would appreciate any assistance you can
> provide in overcoming this error.
> I have attached the error logs.
> Thank you for your time!
> ________________________
> *Bassam Haddad, Ph.D.*
> Post-Doctoral Researcher
> Forschungszentrum Juelich