Problem
I created a simple Cu/Ni FCC binary system to learn how to implement cluster expansions and interpret the data. Using scripts to automate the use of MAPS to perform this cluster expansion, I encounter a segmentation fault error when the expansion reaches one structure in particular.
Background
I SSH into a multi-node compute cluster from a desktop PC. This cluster operates using a queuing system. VASP v5.3 and ATAT are installed in my local bin on the cluster. I wrote a shell script to incorporate the operation of MAPS into the queuing system.
Inputs
My job script:
[header specifying node configuration]
maps -d &
pollmach runstruct_vasp srun
My lat.in was generated automatically using
makelat Ni,Cu fcc
My vasp.wrap:
[INCAR]
System = NiCu Mapstest
ENCUT = 500
ISMEAR = 0
ISPIN = 2
EDIFF = 1E-5
EDIFFG = 1E-3
ISIF = 3
IBRION = 2
POTIM = 0.2
NSW = 100
PREC = N
USEPOT = PAWPBE
KPPRA = 1000
DOSTATIC
KSCHEME = GAMMA
Details
I have tried this system twice with the same set of inputs (although I may have put Cu first in the lat.in for the first attempt). Both times the cluster expansion acted as expected until it reached the structure indexed 264, at which point the program failed, leaving the following error sequence in the vasp.out file:
The errors are were identical for both runs, both occurring when VASP tried to operation on structure 264. Interestingly, The cluster expansion reached 264 sooner on the second attempt. The first time through it was the 39th structure tested, the second time it was the 29th. This may have had something to do with the order of the lat.in. I still have all the data for the second system only if you need any more details.
This is only a test system and I don’t actually need to resolve this error, but I thought you may want to know about it.