Basin hopping is a Monte Carlo method in which the energy of each configuration is taken to be the energy of a local minimum. 1
At each basin hopping step the client will print out the current energy (current), the trial energy (trial), the lowest energy found (global min), the number of force calls needed to minimize the structure (fc), the acceptance ratio (ar), and the current max displacement (md).
steps: Number at steps to take at the assigned temeprature.
default:
10000
displacement: Displacement in each degree of freedom.
default:
0.5
write_unique: If true the client will write out all the unique geometries
that it sees and there energies to files named min_xxxxx.con and energy_xxxxx.con
where the number in the filename corresponds to the monte carlo step where
that structure was first seen. For clusters it is important to set check_rotation
in the [Structure Comparison] section.
default:
false
initial_state_pool_size: The number of lowest energy states in the pool from which the initial structures are drawn. The default value of 1 corresponds to a simulation which will always start from the lowest energy found so far.
default:
1
initial_random_structure_probability: Probability that the initial structure is generated at random.
default:
0.0
push_apart_distance: Push atoms apart until now atoms are closer than this distance. This critera is enforced for the initial structure and all those generated by random displacements. trial move.
default:
0.4
adjust_displacement: Flag to automatically adjust the displacement to meet the target acceptance ratio.
default:
true
adjust_fraction: The fraction by which to change the step size in order to meet the target acceptance ratio.
default:
0.05
adjust_period: The number of Monte Carlo steps between adjustments of the step size.
default:
10
target_ratio: The target acceptance ratio that will be used to determine whether to increase or decrease the step size.
default:
0.5
displacement_distribution: The distribution used for the displacement of each atom.
default:
gaussianoptions:
gaussian: The displacement serves as the standard deviation of a gaussian distribution used to select displacements.
uniform: A random number is selected between -displacement and displacement.
swap_probability: The probability in range [0,1] that a swapping step takes place instead of a displacement step. The swap step selects two atoms of different elements and swaps their position.
default:
0.0
single_atom_displace: Displace only one atom per step.
default:
False
jump_max: The number of consecutive rejected steps after which jump steps should be taken. This serves to provide a more global search when the structure is stuck in a certain basin. The number of jump steps is assigned in jump_steps. See paper on the Basin Hopping with Occasional Jumping algorithm by Iwamatsu and Okabe. 2
default:
0
significant_structure: Displace from minimized structures. 3
default:
True
jump_steps: The number of jump steps to take after the jump_max number of consecutive rejections have taken place.
default:
0
References
D.J. Wales and J.P.K. Doye, “Global optimization by basin-hopping and the lowest energy structures of Lennard-Jones clusters containing up to 110 atoms,” J. Phys. Chem. A 101, 5111 (1997). doi:10.1021/jp970984n
Iwamatsu and Y. Okabe, “Basin hopping with occasional jumping,” Chem. Phys. Lett. 399 396 (2004). doi:10.1016/j.cplett.2004.10.032
R.P. White and H.R. Mayne, “An investigation of two approaches to basin hopping minimization for atomic and molecular clusters,” Chem. Phys. Lett. 289, 463 (1998). doi:10.1016/S0009-2614(98)00431-X