Greetings all, I have a question regarding using kwant for very large systems. In my research I am trying to model graphene-based devices on the order of L = W = 500 nm. I encounter a problem when trying to simulate electron density in these devices with Kwant. The errors I get look like this: Faulting application name: python.exe, version: 0.0.0.0, time stamp: 0x5488acd7 Faulting module name: _mumps.pyd, version: 0.0.0.0, time stamp: 0x54d2a92a Exception code: 0xc00000fd Fault offset: 0x000000000076e357 Faulting process id: 0x5018 Faulting application start time: 0x01d0811ecc4f2ba7 Faulting application path: C:\WinPython-64bit-2.7.9.4\python-2.7.9.amd64\python.exe Faulting module path: C:\WinPython-64bit-2.7.9.4\python-2.7.9.amd64\lib\site-packages\kwant\linalg\_mumps.pyd Report Id: d70446a6-ed26-11e4-9806-b8ac6f4eb471 A little info on the system: I am running 64 bit python installed from the WinPython package. The IDE is Spyder. I've gotten all of the example codes to work as well as several of my own (albeit for smaller versions of the systems we would like to study).
From the error and doing some testing with the code, I've devised that it must be a problem occuring solver itself. I have enough memory to build the system and I am pretty sure I am not running out of memory during the actual solving, although I am not positive. I am wondering if the mumps routine could be breaking for very large systems? When I run my code on a laptop with much less ram (~60 gb for the desktop vs 4 gb on the laptop) I end up with a memory error instead of a kernel crash.
I've attached a modified version of one of the tutorial codes, where I have added in a LDOS/electron density calculation and increased the dimensions of the simulation to 500x1000. The code successfully finalizes the device on my machine, but crashes the python kernel during the actual calculation. I can get more ram for the machine if necessary, but I want to make sure that it isn't a problem related to the solver before sending the purchase order to my advisor. Kwant seems extremely nice so we're hoping to use it in our research in the future! It is a lot better than the NEGF code I strung together in matlab! Thank you! Sam LaGasse