[Wien] PLEASE HELP - PROBLEMS WITH c-AXIS FOR GRAPHENE

[a s]

Hello ML Folks

I am running wien2k_06.4 on a PC (Intel Pentium D) with an Ubuntu 6.06 
operating system (Ubuntu is an open source operating system built around the 
Linux kernel).

I am using a graphite .struct file to calculate the ELNES of graphene, by 
increasing the c-axis spacing in the graphite .struct file.  ‘initialise 
calc’ and ‘run_SCF’ work perfectly.  However, I have problems whenever I 
increase the c-axis spacing beyond a certain threshold (15 Angstoms):

1. Suppose the c-axis spacing is set to 25 Angstroms.  When I run the 'DOS' 
task, in the 'x lapw2 -qtl' step the error message "forrtl: severe (174): 
SIGSEGV, segmentation fault occurred" is flagged.  The DOS, and later the 
ELNES, are then not able to be calculated.

2.  Suppose I use exactly the same .struct file as for 1. above, but modify 
solely the c-axis spacing in the .struct file to 5 Angstroms (and change 
NOTHING else).  Everything works perfectly.  The DOS, and later the ELNES, 
are then able to be calculated.

What am I doing wrong?  Clearly, it cannot be anything to do with the 
.struct file, since as detailed in 2. above, for c=5 Angstroms, everything 
works perfectly.

Any advice greatly appreciated.

Kindest regards

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