MDALGO

MDALGO = 0 | 1 | 2 | 3 | 11 | 21 | 13
Default: MDALGO = 0 

Description: MDALGO specifies the molecular dynamics simulation protocol (in case IBRION=0 and VASP was compiled with -Dtbdyn).

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• MDALGO=0

Standard molecular dynamics (IBRION=0), the same behavior as if VASP were compiled without -Dtbdyn.

• MDALGO=1

NVT-simulation with Andersen thermostat. In the approach proposed by Andersen the system is thermally coupled to a fictitious heat bath with the desired temperature. The coupling is represented by stochastic impulsive forces that act occasionally on randomly selected particles. The collision probability is defined as an average number of collisions per atom and time-step. This quantity can be controlled by the flag ANDERSEN_PROB. The total number of collisions with the heat-bath is written in the file REPORT for each MD step.

• MDALGO=2

Nose-Hoover thermostat (SMASS needs to be specified in the INCAR file).

• MDALGO=3

Langevin dynamics. The Langevin thermostat is controlled by the LANGEVIN_GAMMA and LANGEVIN_GAMMA_L tags.

• MDALGO=11

Metadynamics with Andersen thermostat (see remarks under MDALGO=1 as well).

• MDALGO=21

Metadynamics with Nose-Hoover Thermostat (SMASS needs to be specified in the INCAR file).

• MDALGO=13

Up to three user-defined atomic subsystems coupled with independent Andersen thermostats (see remarks under MDALGO=1 as well).

The POSCAR file must be organized such that the positions of atoms of subsystem i+1 are defined after those for the subsystem i, and the following flags must be set by the user:

• NSUBSYS=[int array]

Define the last atom for each subsystem (two or three values must be supplied). For instance, if total of 20 atoms is defined in the POSCAR file, and the initial 10 atoms belong to the subsystem 1, the next 7 atoms to the subsystem 2, and the last 3 atoms to the subsystem 3, NSUBSYS should be defined as follows:

NSUBSYS= 10 17 20

Note that the last number in the previous example is actually redundant (clearly the last three atoms belong to the last subsystem) and does not have to be user-supplied.

• TSUBSYS=[real array]

Simulation temperature for each subsystem

• PSUBSYS=[real array]

Collision probability for atoms in each subsystem. Only the values 0≤PSUBSYS≤1 are allowed.

Related Tags and Sections

IBRION, ISIF, SMASS, ANDERSON_PROB, RANDOM_SEED, LBLUEOUT, SHAKETOL, SHAKEMAXITER, HILLS_H, HILLS_W, HILLS_BIN, INCREM, STATUS, VALUE_MIN, VALUE_MAX, LANGEVIN_GAMMA, LANGEVIN_GAMMA_L, PMASS

References

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