The use of the symmetric rank-one Hessian update and the Ε½ . BroydenαFletcherαGoldfarbαShano BFGS update formula are considered in an ab initio molecular geometry optimization algorithm. It is noted that the symmetric rank-one Hessian update has an advantage when compared with the BFGS update formul
Efficient geometry optimization of molecular clusters
β Scribed by Baker, Jon; Pulay, Peter
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 185 KB
- Volume
- 21
- Category
- Article
- ISSN
- 0192-8651
No coin nor oath required. For personal study only.
β¦ Synopsis
By combining valence coordinates (stretches, bends, and torsions)
to describe intramolecular degrees of freedom with inverse distance coordinates for intermolecular degrees of freedom, we derive an efficient set of coordinates for the geometry optimization of molecular clusters. We illustrate the efficacy of our new coordinates by considering randomly generated clusters of dihydrogen and water molecules. Compared to optimizations in Cartesian coordinates, the number of cycles required for convergence is reduced by up to a factor of 30. In addition, for the dihydrogen clusters, optimizations using our new cluster coordinates consistently converge to lower energy structures than the corresponding Cartesian optimizations. Our method is far more efficient than optimizations using Z-matrix coordinates, and it avoids all problems with near-linear bond angles that are endemic with a Z-matrix description of the cluster geometry. Additionally, by constraining all the intramolecular degrees of freedom in a completely automated manner, we are able to carry out full rigid-body optimizations.
π SIMILAR VOLUMES
A new implementation of analytical gradients for the polarizable continuum model is presented, which allows Hartree-Fock and density functional calculations taking into account both electrostatic and nonelectrostatic contributions to energies and gradients for closed and open shell systems. Simplifi
Theoretical studies on the electronic and the geometrical structures for various molecules by the molecular orbital or the density functional theory have recently been developed and applied widely under the progress of computer technologies. At present, it is possible to carry out a theoretical inve
The problem of global geometry optimization of clusters is addressed with a phenotype variant of the method of genetic algorithms, with several novel performance enhancements. The resulting algorithm is applied to Lennard-Jones clusters as benchmark system, with up to 150 atoms. The well-known, diff