Hi Jeff, To check the memory limits set by a bash shell use shell command "ulimit -a". For a csh use "limit". Here's an example on my Mac (no memory limit). Tom $ ulimit -a core file size (blocks, -c) 0 data seg size (kbytes, -d) 6144 file size (blocks, -f) unlimited max locked memory (kbytes, -l) unlimited max memory size (kbytes, -m) unlimited open files (-n) 256 pipe size (512 bytes, -p) 1 stack size (kbytes, -s) 8192 cpu time (seconds, -t) unlimited max user processes (-u) 100 virtual memory (kbytes, -v) unlimited Jeff wrote:

I had forgotten about 4-byte floats versus 2-byte integers,

you are right in that this is most likely a machine limitation, I was surprised to get a fault and error about an allocation call. is there a specific environment variable I should check to see if the shell is limiting chimera's memory requests, I will change that if possible (?).

-Jeff