DYNAMICS_VELOCITY_VERLET


Function

Dynamics_Velocity_Verlet contains a procedure for performing a molecular dynamics simulation with a velocity Verlet algorithm.

The basic ideas of molecular dynamics simulations are described in chapters 8 and 10 of the book A Practical Introduction to the Simulation of Molecular Systems. The basic concepts of using the DYNAMO library for dynamics calculations remain the same as described there although there has been a slight rearrangement of the dynamics modules since the book was completed.

Dependencies

Module Variables
DEFINITIONS DP
IO_UNITS OUTPUT
STATUS ERROR
ATOMS ATMCRD, ATMFIX, NATOMS, NFREE
DYNAMICS_UTILITIES Most of the public items in the module.
VELOCITY ATMVEL, EKE, TEMPERATURE, VELOCITY_SCALE, VELOCITY_TEMPERATURE


Public Variables

None.

Public Procedures

There is a single public subroutine in this module.

SubroutinePurpose
VELOCITY_VERLET_DYNAMICS Perform a molecular dynamics simulation using a velocity Verlet algorithm.


VELOCITY_VERLET_DYNAMICS

Argument Type Intent Optional Purpose
TARGET_TEMPERATURE Real In Yes The target temperature for the simulation.
SCALE_FREQUENCY Integer In Yes The step frequency for velocity scaling.
SCALE_OPTION Character ( Len = * ) In Yes The scale option.


Error Meaning
No velocities exist. No velocities have been assigned.
Final temperature not specified for scaling options. The SCALE_OPTION "EXPONENTIAL" or "LINEAR" was specified but the argument TARGET_TEMPERATURE was absent.
Invalid SCALE OPTION. The argument SCALE_OPTION is not one of the strings "CONSTANT", "EXPONENTIAL" or "LINEAR".



Stability

Stable.



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