From: Mayne, Christopher G (
Date: Fri Jun 12 2015 - 11:52:09 CDT


Apologies for taking me a couple of days to get to this. I can confirm that the error is reproducible, and that the error is occurring in the QMtool code when parsing and/or manipulating the hessian data. This is almost certainly because you have modified the route section to read:
 # opt=redundant freq b3lyp/6-31+g(d,p) geom=(connectivity,printinputor
 ient) scf=tight

as opposed to the QMtool (and ffTK) default:
 # MP2/6-31G* Geom=(AllCheck,ModRedundant) Freq NoSymm IOp(7/33=1) SCF=

In the future please include the fact that you have made such modifications in the description of your error. This information is quite pertinent and will likely save others a good deal of time tracking down the source of the error. Modifications to the route section will almost certainly change the structure/details of the output Gaussian log file. QMtool uses specific keywords to parse the desired data from this file, and I suspect that something has changed with these keywords in the output due to the modified route section.

I will try to track down where the keyword mismatch is occurring, but it will have to wait until next week. From the input route section it appears that you want to change the basis set used for the calculation. I'll assume that you have good reason for this, so in the meantime you might try using the QMtool/ffTK default route section only modifying the basis set / level of theory option (i.e., leave the rest alone) and see if the output is compatible with QMtool's parsers. Something like:

# b3lyp/6-31+g(d,p) Geom=(AllCheck,ModRedundant) Freq NoSymm IOp(7/33=1) SCF=

Christopher Mayne

On Jun 8, 2015, at 9:59 PM, Mohan maruthi sena wrote:

Dear Sir,
             Thanks for a reply. Please find the required files as attachment.

Thanks & Regards,
K. Mohan

On Mon, Jun 8, 2015 at 10:26 PM, Mayne, Christopher G <<>> wrote:

The error appears to be occurring deep within the QMTool procs. Can you send me the following files (files used in the Opt. Bonded "Input" section)?

PDB containing optimized geometry
PSF containing optimized charges
LOG file from the Gaussian calculation of the Hessian
PAR files for the in-progress parameter file and any associated parameter files

I'll see if I can reproduce the error and then track down the problem.

Christopher Mayne

For future reference, questions regarding ffTK are typically (although not always) more appropriate for VMD-L rather than NAMD-L.

Date: Sun, 7 Jun 2015 05:05:44 +0530
From: Mohan maruthi sena <<>>
Subject: namd-l: FFTK - error

Hi all,
          I am trying to generate parameters for a molecule using fftk. I
am currently using vmd 1.9.2 version. After performing optimization of
molecule in gaussian, I perform hessian calculations to generate bonded
parameters. When i try to generate bonded parameters, the following error
message is displayed,

. can't use empty string as operand of "/"
can't use empty string as operand of "/"
   while executing
"expr {$fc/double($n*$n)}"
   (procedure "assign_fc_zmat" line 37)
   invoked from within
"assign_fc_zmat $inthessian_kcal"
   (procedure "::QMtool::load_gaussian_log" line 56)
   invoked from within
"::QMtool::load_gaussian_log $hessLog $hessLogID"
   (procedure "::ForceFieldToolKit::BondAngleOpt::optimize" line 81)
   invoked from within
   (procedure "::ForceFieldToolKit::gui::baoptRunOpt" line 40)
   invoked from within
"::ForceFieldToolKit::gui::baoptRunOpt "
   invoked from within
".fftk_gui.hlf.nb.bondangleopt.runOpt invoke "
   invoked from within
".fftk_gui.hlf.nb.bondangleopt.runOpt instate {pressed !disabled} {
.fftk_gui.hlf.nb.bondangleopt.runOpt state !pressed;

Can you please suggest me a way to overcome this error.

Thanks & Regards,
Mohan Maruthi