From: Mayne, Christopher G (
Date: Thu May 02 2013 - 13:51:37 CDT


The input file will pull a lot of structural information from the CHK file provided from the geometry optimization. However, the hessian input file you are referring to should also contain a set of data that redefines the internal coordinates that you are not seeing.

We've made a lot of updates and improvements to this portion of ffTK. You should make sure that you're using the latest version, included with the most up-to-date alpha release of VMD, available from BioCoRE (

Christopher Mayne

On May 2, 2013, at 10:26 AM, aravind chandrasekaran wrote:

> In step 6 (bond calculation), we need to upload the .chk file and specify the output gaussian file to write a gaussian input job file. Upon doing it (following all steps as per tutorial till step 5), the gaussian file reads the following,
> *******
> %chk=C:/Users/Aravind/Desktop/prld-hess.chk
> %nproc=4
> %mem=4
> # MP2/6-31G* Geom=(AllCheck,NewRedundant) Freq NoSymm Pop=(ESP,NPA) IOp(6/33=2,7/33=1) SCF=Tight
> Which literally means an empty gaussian file with just file headers. Is this an error or can we proceed with the hessian calculation with this file?
> Thanks,
> Regs
> ,
> AC.