On Sun, September 13, 2009 14:04, Ihsan Erikat wrote: > when I put job for 2x2 surface the cluster work very well but when I put > the job for 4x2 surface it give me this error > Fortran runtime error: ALLOCATE: Out of memory. on the shell
Dear Ihsan, the error message is quite clear: your hardware does not have enough memory for the calculation you are trying to do! There are a few measures you can take to reduce the memory usage: 1. if you are using pools, reduce the number of pools, it requires more communication between nodes, but reduces the memory usage. 2. if you are using norm-conserving pseudopotentials try ultrasoft or PAW instead; more in general try to do more accurate test on convergence with respect to wfc and rho cutoff 3. if you have a slab geometry you may still have good results reducing the amount of vacuum (you'll have to test the convergence wrt the amount of vacuum) 4. if you are using a computation cluster, run the code on more processors 5. if you are using a PC, buy more RAM 6. us cg instead of david diagonalization, but only as a last measure best regards -- Lorenzo Paulatto SISSA & DEMOCRITOS (Trieste) phone: +39 040 3787 511 skype: paulatz www: http://people.sissa.it/~paulatto/ ---------------------------------------------------------------- SISSA Webmail https://webmail.sissa.it/ Powered by SquirrelMail http://www.squirrelmail.org/
