|From:||Axel Kohlmeyer <akohlmey@...24...>|
|Date:||Mon, 14 Aug 2017 04:57:17 -0400|
Dear Dr. Axel Kohlmeyer,Hello Dr. Kohlmeyer. Thank you for your e-mail.I was curious if my understanding is correct.
If my input script contains a command line such as "velocity all create 1.0 1483274" and run this script many times, the random seed will ensure that I will reproduce the exact same results when I run the same script multiple times.
However, if my input script has "pair_style dpd 1.0 1.0 1224589" or any other command such as "fix langevin" that has a thermal input argument, there is no guarantee that I will reproduce the exact same results for every same run due to the inevitable "thermal noise."Furthermore, if I have dpd pairwise command where the pairwise coefficient frequently changes for every 50 timesteps like the example below, the random seed will not be able to reproduce same results.
pair_style dpd 1.0 1.0 122347
pair_coeff * * 25 4.5 1.0
pair_coeff * * 50.0 4.5 1.0
velocity all create 1.0 15086120
pair_coeff * * 100.0 4.5 1.0
velocity all create 1.0 15786120
pair_coeff * * 150.0 4.5 1.0
velocity all create 1.0 15486120
Overall, I was curious if you suggest that these slight variations in data reproduction should not be an issue since the deviation is marginal.
Thank you.Sincerely,Masato Koizumi