From: Michail Palaiokostas Avramidis (
Date: Tue Jan 27 2015 - 09:20:46 CST

Dear VMD users,

while trying to use catDCD, I encountered a problem and I would like your opinion. My VMD version is 1.9.2 (December 29, 2014).

I first loaded the two dcd files that I want to merge, together with their .psf. Then I tried to execute the command:

catdcd -o eq_all.dcd eq01.dcd eq02.dcd

but I got the error:

-code 1 -level 0 -errorcode {CHILDSTATUS 19788 1} -errorinfo {CatDCD 5.1
Reading indices from file 'eq01.dcd'
Error: no indices found in file.
    while executing
"::exec /usr/local/lib/vmd/plugins/LINUXAMD64/bin/catdcd5.1/catdcd -stride eq02.dcd -i eq01.dcd -o eq_all.dcd -o"
    ("eval" body line 1)
    invoked from within
"eval ::exec [list $exec_path] [lrange $args 1 end]"
    (procedure "::ExecTool::exec" line 14)
    invoked from within
"::ExecTool::exec catdcd -stride $stride -i $indexFile -o $outFile $dcdFileNames"
    ("eval" body line 1)
    invoked from within
"eval ::ExecTool::exec {catdcd -stride $stride -i $indexFile -o $outFile $dcdFileNames} "} -errorline 13

If I try to execute the same command with the catdcd binary (found in the VMD plugin library) from the terminal, the program runs just fine and I get the concatenated file.

Do you think is a bug or I am doing something wrong? Have you encountered this before?

Best Regards,


Michail (Michalis) Palaiokostas-Avramidis
PhD Student
School of Engineering and Materials Science
Queen Mary, University of London
United Kingdom
LinkedIn Profile<>