# simulated_annealing

Apply simulated annealing in an MD simulation. For this to work properly, thermostat must also be specified. This command can appear in the global context.

### Options

cooling_scheme

Specify the cooling scheme.

• The type is string
• The default is linear
• The value must be one of:
• linear - Use the linear cooling scheme.
• logarithmic - Use the logarithmic cooling scheme of the form: $$T = \frac{T_0}{\log (t + 10)}$$ where $$T_0$$ is the initial temperature, and $$t$$ is the current time.
cooling_sequence

Specify the annealing sequence as a list. Each list element should be a tuple with [time, temperature]; time must be in picoseconds, and temperature must be in kelvin. for example: cooling_sequence = [[0, 600], [2, 550], [4, 500]] will first raise the system temperature to 600 K at 0 ps, and then decrease the temperature to 550 K between 0 ps and 2 ps; then decrease the temperature to 500 K between 2 ps and 4 ps; after that, the temperature stays constant at 500 K until the simulation finishes.

• The type is [(real, real)]
• There is no default value.
cooling_time

The time length for cooling of the system.

• The type is quantity
• The default is 50.0 ps
• The value must be positive
final_temperature

Specify the final temperature for simulated annealing. The final temperature is preferrably low enough to reach the ground state in a fast cooling.

• The type is quantity
• The default is 200.0 kelvin
• The value must be positive
initial_temperature

Specify the initial temperature for simulated annealing. The initial temperature is preferrably higher or equal to the largest energy barrier of the system.

• The type is quantity
• The default is 1000.0 kelvin
• The value must be positive