UT theoretical chemistry code forum

Dear VTSTcode users,
I downloaded the latest vtstcode.tar.gz to our IBM P690 machine (AIX with xlf). I have compiled and ran the standard VASP 4.6 on this machine without any problem.
I'd like to apply VTSTcode to my research. Therefore,
I compiled the vasp.4.lib code at first. The makefile was the default makefile for RS6000 in vasp.4.lib folder. It works without any problem. Then, I just followed the building guidelines of vtstcode: copied the source codes of vtstcode into the vasp.4.6 folder and add the following objects, "tet.o hamil.o steep.o dimer.o dynmat.o neb.o lanczos.o \
sd.o cg.o qm.o lbfgs.o bfgs.o fire.o opt.o \ ", into the Makefile, which is the default makefile for rs6000 in vasp.4.6 folder.

I encountered the error messages listed in the following:
xlf90 -O4 -qarch=auto -c chain.f
"chain.f", line 147.13: 1511-025 (S) Logical expressions must only be compared using EQV and NEQV operators.
"chain.f", line 147.28: 1511-025 (S) Logical expressions must only be compared using EQV and NEQV operators.
** chain === End of Compilation 1 ===
1501-511 Compilation failed for file chain.f.
make: 1254-004 The error code from the last command is 1.


Could anyone give me some guidelines for tackling this problem?
Thank you very much.
Sincerely,
James

Thanks for pointing out this problem. The code has been updated to avoid the statement that xlf is complaining about.

[quote="graeme"]Thanks for pointing out this problem. The code has been updated to avoid the statement that xlf is complaining about.[/quote]
I appreciate your help and great effort.
I have already compiled vtstcode in IBM P690 machine successfully.