From: Bassam Haddad (
Date: Thu Sep 30 2021 - 11:07:34 CDT

Hi Mariano,

I was able to make it through the tutorial without any problems, however I
am encountering an odd error when I attempt to paramaterize salicylate.

I can make it through the second ORCA step, and then ffTK fails at the
water-optimization step with the following error:

"measure fit: selections must have the same number of atoms"

I've checked all of the outputs from ORCA and they all contain 18 atoms (15
from SAL + 3 from water) so I am having trouble pinning down the source of
the error -- the first base-water.psf/pdb that is generated also has 18
atoms, so again I am not sure where the error is coming from.

Any insite/suggestions you or anyone else has for me would be greatly


On Tue, Sep 28, 2021 at 9:43 PM Mariano Spivak <> wrote:

> Hi Bassam,
> Sorry for delayed reply, we had a very busy week.
> Could you check if the ORCA run generated a file that ends with
> *_job2_internal.hess?
> You should be able to use the hess.out in FFTK without any issue.
> The error you see in the hess.out file occurs in the job2 run, which is
> there only to obtain the hessian in internal coordinates. So no need to
> worry about that error, sorry for the confusion.
> Let me know if you encounter any other issues.
> Best
> On Sep 27, 2021, at 7:43 AM, Bassam Haddad <> wrote:
> Hi Mariano,
> I got the same error as mentioned above, even when running orca on the
> example hess.inp file from your ks.uiuc web-page. I am at a loss for how to
> get this optimization to work, do you have an idea of what I can do to
> increase the maxiter as the program requests? Furthermore I have the same
> error when using ORCA_4.1.1 and ORCA_5.0.0. Below I have attached the input
> and output files.
> Thank you,
> Bassam
> On Tue, Sep 21, 2021 at 8:15 PM Bassam Haddad <> wrote:
>> Hi All,
>> ORCA is terminating early due to lack of convergence in the geometry
>> optimization calculation during step-4 (4-baOpt). I tried increasing the
>> 'maxiter' in the ETOH.hess.inp file, however it fails every time regardless
>> of how high i set it. When I do run the calculation, it notifies me that
>> it's setting the maxiter to 0, regardless of what I put as the max
>> iteration.
>> I have attached my input and output from my failed run.
>> I appreciate any help you can provide.
>> Thanks,
>> Bassam
>> On Tue, Sep 21, 2021 at 5:34 PM Bassam Haddad <> wrote:
>>> Hi Mariano,
>>> Thank you for your reply. I was able to resolve the issue by installing
>>> orca_4.1.1 (the version in the ffTK tutorial). My issues were with
>>> orca_5.0.0.. I hadn't run anything differently, so I assume it was an error
>>> due to version differences.
>>> Best,
>>> Bassam
>>> On Sun, Sep 19, 2021 at 8:20 PM Mariano Spivak <>
>>> wrote:
>>>> Hi Bassam,
>>>> The bond/angle optimization step in FFTK using ORCA generates one input
>>>> file (e.g. hess.inp) that contains two calculations in sequence, the file
>>>> “initial.hess” is generated by the first calculation.
>>>> The error you see ORCA report is most likely due to from some error
>>>> termination in the first calculation (e.g. issues with memory, not
>>>> converged).
>>>> Try repeating the calculation or you can send the generated files and I
>>>> can take a look at the issue.
>>>> Hope this helps.
>>>> Best
>>>> On Sep 18, 2021, at 11:02 AM, Bassam Haddad <> wrote:
>>>> 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 calculations?
>>>> Thank you for your time!
>>>> Bassam
>>>> 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
>>>> <hess.inp><hess.out>