hello all. i'm sorry to bother everyone again, but i have determined a little more information regarding my restart problem. first of all i have found the problem to occur on two different 32 bit platforms but not on the only 64 bit processor that i have tested. moreover it occurs both for 1cpu and muli-cpu jobs and irrespective of whether i compile with gnu/intel or with/without ia32_sse loops. the problem persists when i am running nve simulations so thermo/baro stat coupling is not the problem.
it appears that when i use tpbconv to continue a simulation, it reads in the positions and velocities with high accuracy. if i try to extend a 1 step simulation with dt-->0, then i find that x are correct to within 1 part in 1e14 (using double or single precision). however i find that the forces are only correct to within 1 part in 1e3 (again independent of the precision for which i tried to compile). in fact if i look in the mdrun log file i find that the LJ(SR) energy differ at 1 part in 1e5 between calculations for the last config of the first simulation and the calculation for the (0 step) first config of the continuation simulation. i would have expected these numbers to be exactly the same since they are both calculated from what appears to be the same configuration. why is there so much inconsistency in the force calculation and even in the LJ(SR) energy? is this to be expected? am i missing something? anyway thanks to anyone who took the time to look at this. any help would be greatly appreciated. peace, will noid _______________________________________________ gmx-users mailing list [EMAIL PROTECTED] http://www.gromacs.org/mailman/listinfo/gmx-users Please don't post (un)subscribe requests to the list. Use the www interface or send it to [EMAIL PROTECTED] Can't post? Read http://www.gromacs.org/mailing_lists/users.php
