VMD-L Mailing List

From: Gumbart, JC (gumbart_at_physics.gatech.edu)
Date: Thu Apr 07 2022 - 08:34:27 CDT

Hi Rahul,

Can you send me your files off list with instructions of what you did to generate that error? I will try to reproduce it in order to track down the cause.

Best,
JC

> On Apr 5, 2022, at 7:46 PM, Rahul Nikhar <rnikhar_at_udel.edu> wrote:
>
> Dear developers/users,
>
> I have successfully used ffTK for fitting intramonomer parameters for a small molecule (called mon1 which has 16 atoms). I used Orca 5.0.1 for my QM calculations.
> Now, I have been trying to perform such a calculation for a slightly larger molecule (called mon2 which has 27 atoms), larger only when compared to mon1.
> Since fitting parameters for mon1 was straightforward, I was surprised that I am facing issues for mon2.
> When I tried to optimize bonds/angles, I got an error given at the end of the email.
> I found a thread from 2014 from a simple google search where the developer (Christopher) solved such an issue for one of the users of ffTK.
> As suggested in that thread, I checked if my calculation of Hessians was successfully completed.
> This was even easy for my case, as I compared the output files of mon1 (successful run) against mon2.
> It doesn't look like there is an issue with the calculation.
> I checked the tcl file (fftk_QMORCA.tcl), which reads the information from the output file and determines whether the calculation was successful, and it seems okay.
> All of the information searched ("FINAL ENERGY EVALUATION AT THE STATIONARY POINT", "THE OPTIMIZATION HAS CONVERGED") by $inLine are found in the output file.
>
> I am not sure how to debug this problem.
> Any insight will be very much appreciated.
>
>
> ERROR from ffTK
>
> ===================================================
> can't use empty string as operand of "*"
> can't use empty string as operand of "*"
> while executing
> "expr {($kc)*$h1up*$h2up}"
> (procedure "::ForceFieldToolKit::BondAngleOpt::computePESqm" line 206)
> invoked from within
> "::ForceFieldToolKit::BondAngleOpt::computePESqm $hessLogID"
> (procedure "::ForceFieldToolKit::BondAngleOpt::optimize" line 91)
> invoked from within
> "::ForceFieldToolKit::BondAngleOpt::optimize"
> (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 !disabled { .fftk_gui.hlf.nb.bondangleopt.runOpt invoke } "
> invoked from within
> ".fftk_gui.hlf.nb.bondangleopt.runOpt instate pressed { .fftk_gui.hlf.nb.bondangleopt.runOpt state !pressed; .fftk_gui.hlf.nb.bondangleopt.runOpt insta..."
> (command bound to event)
> ===================================================
>
> Best,
> Rahul
>
>