RANDOM SEED: Difference between revisions
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The seed for the RNG determines the trajectory a molecular-dynamics simulation takes. | The seed for the RNG determines the trajectory a molecular-dynamics simulation takes. | ||
Set the {{TAG|RANDOM_SEED}} tag to reproduce a previously performed calculation. | Set the {{TAG|RANDOM_SEED}} tag to reproduce a previously performed calculation. | ||
The three integers of {{TAG|RANDOM_SEED}} must fulfill these conditions: | |||
0 <= RANDOM_SEED(1) < 900000000 | |||
0 <= RANDOM_SEED(2) < 1000000 | |||
0 <= RANDOM_SEED(3) | |||
A typical input for the {{TAG|RANDOM_SEED}} looks like this: | A typical input for the {{TAG|RANDOM_SEED}} looks like this: | ||
Revision as of 12:56, 23 March 2023
RANDOM_SEED = [integer][integer][integer]
Default: RANDOM_SEED = based on the system clock
Description: RANDOM_SEED specifies the seed of the random-number generator (compile VASP with -Dtbdyn).
The random-number generator (RNG) generates a sequence of random numbers for molecular-dynamics simulations for example to initialize atomic velocities and for the Andersen thermostat (MDALGO=1 | 11). The seed for the RNG determines the trajectory a molecular-dynamics simulation takes. Set the RANDOM_SEED tag to reproduce a previously performed calculation. The three integers of RANDOM_SEED must fulfill these conditions:
0 <= RANDOM_SEED(1) < 900000000 0 <= RANDOM_SEED(2) < 1000000 0 <= RANDOM_SEED(3)
A typical input for the RANDOM_SEED looks like this:
RANDOM_SEED = 248489752 0 0
The initial value of RANDOM_SEED and the value after each MD step are written to the REPORT file.
| Tip: The random seed is used to improve reproducibility of exact numbers during every step. If the time-averaged results depend on the random seed, the ensemble is not big enough, i.e., the molecular-dynamics simulation time is too short. |