In order for this version of Eclipse to run, GTK2 libraries and their dependencies
must be installed and available on the library path (i.e. LIBPATH).  These libraries
are available from http://www-03.ibm.com/systems/power/software/aix/linux/toolbox/alpha.html .
To determine the full set of libraries required for installation, download and install the
"gtk2" rpm, at which time any missing dependencies will be listed.  These dependencies should
be available for download from the same site.

You can run Eclipse using the VM from IBM Developer Kit for AIX versions
5 and 6.  The IBM Developer Kit for AIX can be downloaded from:
https://www.ibm.com/developerworks/java/jdk/aix/service.html

There is a bug in the Oracle Java 7 64-bit JRE (b147) which may cause Eclipse
to crash (http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7070134).  
The crash can be avoided by using the -XX:-UseLoopPredicate VM argument 
(-vmargs -XX:-UseLoopPredicate).  Alternatively, you can use a different JRE.