[gmx-users] Converting a new-version .tpr file to an old-version .tpr file

[Andrew DeYoung]

Hi,

I ran a simulation using Gromacs 4.5.5.  However, I would like to use g_sdf
to compute a spatial distribution function.  As mentioned in a post (
http://lists.gromacs.org/pipermail/gmx-users/2012-March/069073.html ), this
old no longer available g_sdf might be more flexible than g_spatial in some
cases.  So, I fed my .tpr file which was created using Gromacs 4.5.5 into
g_sdf using Gromacs 4.0.5 (I have both versions on my computer).  When I
tried this, I got the following error message:

-------------------------------------------------------
Program g_sdf, VERSION 4.0.5
Source code file: tpxio.c, line: 1683

Fatal error:
reading tpx file (nvt2dy.tpr) version 73 with version 58 program
-------------------------------------------------------

This is a strange question, but is it possible to convert a .tpr file from
version 73 back to version 58?

Thanks so much,

Andrew DeYoung
Carnegie Mellon University