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OPTIM includes a number of methods for locating transition states and characterising the corresponding pathways. OPTIM has analytic first and second derivatives coded for dozens of empirical potentials, and can also treat systems involving periodic boundary conditions and solve general optimization problems, such as least squares fits. Visit the OPTIM website for further information.
Visit the PATHSAMPLE website for further information.
This program employs the basin-hopping algorithm described by Wales and Doye (J. Phys. Chem. A, 101, 5111, 1997) to locate global minima on a potential energy surface. Many potentials are included. The latest version also includes implementations of basin-sampling and parallel tempering. GMIN website for further information.
This scheme has been integrated with GMIN, OPTIM, and PATHSAMPLE. Further information of the RBAA scheme can be found here.
This program can find the effective molecular symmetry group for a non-rigid molecule given the minimal set of generators for the rigid molecule point group and the feasible rearrangements. The associated character tables, tunneling splitting patterns and nuclear spin weights can be generated automatically. Please contact David Wales for further information.
The new version of the disconnectivity graph program that reads standard PATHSAMPLE output files is available under the GPL as part of the current svn software image from the group, together with the manipulate program. The documentation consists of the commented lines at the start of each source file.
This mouse-based program can be used for viewing multiple-frame XYZ files. Bonding and hydrogen-bonding information is visualized and properties such as the atomic positions and visibility can be modified interactively. In addition, inter-atomic distances and angles can be measured. For further details please contact Matt Hodges. XMakemol page.
These programs have been tested with Mathematica 3. For further details please contact David Wales. The notebook can be downloaded here.
ORIENT is a program for carrying out calculations of various kinds for an assembly of interacting molecules. It uses a site-site potential specified by the user, including electrostatic, induction, repulsion, dispersion and charge-transfer interactions if required. The electrostatic interactions may be described by simple point charges or by more elaborate descriptions involving distributed multipoles up to rank 5 if required. Distributed polarizabilities may be used if required, and the site-site repulsion and dispersion and charge-transfer terms may be anisotropic. The energy of the assembly can be calculated at specified configurations, and the geometry can be optimized to find minima and transition states and the paths between them. Molecular dynamics and Monte Carlo calculations can be performed on the assembly.
Please visit A.J. Stone's homepage to download the program.
This program changes the atom orders for some IMPROPER's in the topology file made by LEaP to obtain a potential that is symmetric with respect to permutations of exchangeable atoms. For the new topology file the energy is invariant to permutation of such atoms or groups. The program works for all atom representations of amino and nucleic acid residues that are present in the following Amber9 libraries: all_amino02.lib, all_aminont02.lib, all_aminoct02.lib, all_nucleic02.lib for ff02 and all_amino03.lib, all_aminont94.lib, all_aminoct94.lib, all_nucleic02.lib for ff03. Please consider modification of this program if you would like to take into account other residues or molecules, i.e. ligands. Two versions of this program for two force fields can be downloaded here for ff02 ff03 .
Rotations of the side chains of amino acids can map an initial structure onto
a permutational isomer, which should have the same energy and structure.
However, some rotamers modelled by the CHARMM potential
can have slightly different energies even if tightly converged,
which caused us some bookkeeping issues in discrete path sampling calculations.
These energy differences originate from how the dihedral contribution to the
energy function is defined. We have changed these definitions to symmetrise
the rotamer potentials for ARG, ASN,
TYR, PHE, GLU, ASP, VAL, and LEU in the CHARMM19 potential.
We have also symmetrised the CTER improper torsion.
You can download these modified topology and parameter files for CHARMM19 here:
[ toph19_perm.inp] [ param19_perm.inp] [ toph19_eef1_perm.inp] [ param19_eef1_perm.inp]