The DL-FIND geometry optimisation library

DL-FIND is an open-source geometry optimisation library for atomistic simulation codes. It provides methods for local minimisation, transition state search, reaction path optimisation, conical intersection optimisation and population-based (global) optimisation.

A well-defined interface is provided to make it straightforward to integrate the DL-FIND library into computational chemistry software packages. DL-FIND is an integral part of STFC’s ChemShell QM/MM code and GAMESS-UK quantum chemistry code, and has been interfaced to several other programs.

The DL-FIND project was started by Johannes Kästner in 2006. The code developers are Jo Carr, Johannes Kästner, Tom Keal and Judith Rommel. DL-FIND is currently maintained for STFC by Tom Keal.

Features

Coordinate systems

• Optimisations may be carried out in:
  • Cartesian coordinates (including frozen atoms and components)
  • Delocalised internal coordinates (DLCs)
  • Hybrid delocalised coordinates (HDLCs)
  • Total connection (DLC-TC/HDLC-TC)
• Input/output is in Cartesian coordinates (transformed internally as required)

Local minimisation algorithms

• Steepest descent
• Conjugate gradient
• Newton-Raphson/quasi-Newton (BFGS)
• L-BFGS (low memory quasi-Newton) for large systems
• Damped dynamics

Transition state search

• Partitioned rational function optimisation (P-RFO) with Powell or Bofill updates
• Dimer method

Reaction path optimisation

• Nudged elastic band (NEB) method

Conical intersection optimisation

• Penalty function
• Gradient projection
• Lagrange-Newton

Population-based optimisation

• Genetic algorithm
• Stochastic search

Parallel methods

• The following methods can be run in parallel using DL-FIND’s task-farming interface:
  • NEB
  • Genetic algorithm
  • Stochastic search
  • Finite-difference Hessian evaluation

Restart mechanism

• DL-FIND is fully restartable.

Acknowledgements

• The HDLC coordinate transformation routines in DL-FIND are derived from the HDLCopt code written by Salomon Billeter and Alexander Turner. This code is included by permission of the Max-Planck-Institute für Kohlenforschung.
• The L-BFGS code by Jorge Nocedal was used.

GPR optimisation

If you wish to use the recently developed Gaussian Process Regression optimisation features in DL-FIND, you can download a development version of DL-FIND with GPR.

Citing DL-FIND

Publications making use of the DL-FIND geometry optimiser either through ChemShell or as a standalone library should cite:

• DL-FIND: an Open-Source Geometry Optimizer for Atomistic Simulations, J. Kästner, J. M. Carr, T. W. Keal, W. Thiel, A. Wander, P. Sherwood, J. Phys. Chem. A, 2009, 113, 11856.

DL-FIND development

The DL-FIND repository is hosted on STFC Gitlab. If you are interested in contributing to the development of DL-FIND, please contact Tom Keal.