Basin Hopping TutorialΒΆ

This tutorial explains how to run a basin hopping global optimization calculation on a Lennard-Jones 13 particle.

_images/lj13.png

Here is the con file of our starting structure:

Generated by tsase

101.942400	103.142600	102.605500
90.000000	90.000000	90.000000


1
13 
1.000000 
H
Coordinates of Component 1
  50.594227	  52.017165	  52.277482	0	0
  51.578540	  52.642148	  51.195222	0	1
  51.243758	  52.919086	  52.218383	0	2
  50.490127	  52.736378	  51.417663	0	3
  51.522643	  50.884535	  51.656125	0	4
  50.927263	  51.743087	  51.272643	0	5
  51.240676	  50.960436	  50.573042	0	6
  51.275727	  52.061877	  50.284160	0	7
  50.434110	  50.976423	  51.879062	0	8
  51.695007	  51.919472	  52.038680	0	9
  51.363596	  52.199101	  53.064923	0	10
  52.017483	  51.639074	  51.008389	0	11
  51.187843	  51.165217	  52.678225	0	12

Here is the config.ini file:

[Main]
job=basin_hopping
# specify the temperature used in the Monte-Carlo step acceptance
temperature=500

[Potential]
# use the lennard-jones potential, in reduced-units
potential=lj

[Communicator]
# run the client locally
type=local
# only run 1 client at a time
number_of_cpus=1
# run 10 jobs per invocation of eon
num_jobs=10
# search $PATH for a binary named eonclient
client_path=eonclient

[Basin Hopping]
# perform 100 Monte-Carlo steps
steps=100
# use a gaussian distribution for the displacements instead of a uniform distribution
displacement_distribution=gaussian
# the standard deviation for the gaussian which is used to displace each degree of freedom
displacement=0.3

[Optimizer]
# use the lbfgs optimizer
opt_method=lbfgs
# stop the optimization once the max force per atom drops below 0.001 eV/A
converged_force=0.001
# specifies the value of 1/H0 used in the lbfgs optimizer
lbfgs_inverse_curvature=0.01

You should now have a directory with two files in it: config.ini and reactant.con. To run the calculation run the eon script:

$ eon
registering results
0 (result) searches processed
0 searches in the queue
making 10 searches
10 from random structures 0 from previous minima
job finished in .//jobs/scratch/0
job finished in .//jobs/scratch/1
job finished in .//jobs/scratch/2
job finished in .//jobs/scratch/3
job finished in .//jobs/scratch/4
job finished in .//jobs/scratch/5
job finished in .//jobs/scratch/6
job finished in .//jobs/scratch/7
job finished in .//jobs/scratch/8
job finished in .//jobs/scratch/9
10 searches created

Eon first looks for any completed jobs. As this is the first time you have run Eon, it finds no previous calculations to register. It then makes the input files needed for the 10 basin hopping jobs and writes them to jobs/scratch/0..9. Then eonclient is run in each of these directories.

EON

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