RANDOM SEED: Difference between revisions

Revision as of 07:34, 7 April 2022

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.

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.

@@ Line 1: / Line 1: @@
-{{DISPLAYTITLE:RANDOM_SEED}}
+{{DISPLAYTITLE: RANDOM_SEED}}
 {{TAGDEF|RANDOM_SEED|[integer][integer][integer]|based on the system clock}}
-Description: {{TAG|RANDOM_SEED}} specifies the seed of the random-number-generator (in case VASP was compiled with [[Precompiler_flags|-Dtbdyn]]).
+Description: {{TAG|RANDOM_SEED}} specifies the seed of the random-number generator (compile VASP with [[Precompiler_flags|-Dtbdyn]]).
 ----
-The random-number generator (RNG) is used at several instances of a molecular-dynamics simulation such as the initialization of atomic velocities, the Andersen thermostat ({{TAG|MDALGO}}=1 {{!}} 11), etc. The seed for the RNG can be supplied by the user by means of the {{TAG|RANDOM_SEED}}-tag. This is useful, for instance, if one needs to reproduce a previously performed calculation.
+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 ({{TAG|MDALGO}}=1 {{!}} 11).
+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.
-An input for the random seed should look like the following:
+A typical input for the {{TAG|RANDOM_SEED}} looks like this:
   {{TAGBL|RANDOM_SEED}} =         248489752                0                0
-The initial value of {{TAG|RANDOM_SEED}}, and the value after performing each MD step are written in the {{FILE|REPORT}} file.
+The initial value of {{TAG|RANDOM_SEED}} and the value after each MD step are written to the {{FILE|REPORT}} file.
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