Hello all, First let me warn you that this is a bit of an involved question, but I have spent some time on it and have been unsuccesfull in finding a solution. Thanks in advance for any help you can provide. This list has been a critical factor in my success in this past summer internship.
I am in the process of optimizing a basis for a complex inorganic unit cell (Orthorhombic cell with a, b and c on the order of 5, 5 and 36 Angstroms respectively). It contains a rare-earth and transitional metal perovskite phase between bismuth oxide layers. I eventually hope to study the band structure. As you might imagine, getting the SCF calculation to finish with a simple "confinement-energy" basis was a process in itself. I started with an electronic temperature of 1000K and a mixing weight of 0.0001. Periodic restarts were necessary to shorten the steps between kicks. Once the SCF converged, I'd lower the electronic temperature and start again, untill I got to 0 K. Now I am running into serious problems with optimizing a basis for the system. First, I would run the initial calculation on 6 nodes. As far as I can tell, the Simplex utility included with Siesta cannot be made to drive a program in parallel (adding an mpi execute command to the run_script crashes the optimization routine). So currently I am stuck running each indivdual job to calculate the basis enthalpy on one node, which looks to make the job about three weeks long. Also, I've found that I cannot use the above iterative restart process for completing the SCF calculation when optimizing my basis. That is, restarts of jobs are not permitted using simplex. Has anybody encountered issues such as these? I can't imagine that everyone optimizes their basis using one node per job. Also, how necessary is an optimized basis for what I am interested in? Particularly, I want to be able to report the primary character of the top of the valence band and the bottom of the conduction band. Thanks so much for all of your help so far! Rob Koch B.S. Candidate, Ceramic Enginnering Inamori School of Engineering, Alfred University
La2.fdf
Description: La2.fdf
