SCIGRESS - Computational Tools
Computational tools implemented in SCIGRESS:
- Molecular Mechanics
Mechanics is used by SCIGRESS to optimize molecular structures using an augmented version of Allinger's standard MM2 and MM3 classical force field.
Dynamics methods use classical, empirical force fields to approximate the movement of atoms. The dynamics application uses the same force fields (MM2 and MM3) as the Mechanics application. Use dynamics to visualize conformations that occur as a result of molecular motion; discover information regarding the structure-energy relationships of the molecule; investigate conformational space occupied by the system at varying temperatures.
- Molecular Dynamics (MD-ME)
MD-ME is an advanced molecular dynamics module that can be used to study the molecular dynamics of model systems including crystals, polymers, dendrimers, etc. MD-ME implements a wide variety of force fields that can be used with organic and non-organic models.
The DGauss program is designed to compute the energetics and properties of molecules using DFT.The theory includes dynamic correlation and thus can be expected to yield results of high accuracy. The method is applicable to covalent, ionic, as well as metallic systems.
- MO-G (MOPAC)
MO-G is a general-purpose semi-empirical molecular orbital package. Use MO-G to calculate the vibrational spectra, thermodynamic quantities, isotopic substitution effects and force constants for molecules, radicals, ions, and polymers. For studying chemical reactions a transition state location routine is also available.
CONFLEX generates low energy confomers of a molecule of any shape. Use CONFLEX to compute optimum geometries, conformations and potential energy maps.
ZINDO computes semi-empirical quantum mechanical values for molecular properties and spectra of molecules. ZINDO uses theoretically-based INDO parameterization and therefore contains parameters for more elements than does the experimentally-based MO-G or MO-S. However, because MO-G has been specifically parameterized for ground-state heats of formations MO-G is the better method for computing molecule structures and energetics. Use ZINDO to carry out calculations of electronic UV-visible absorptions spectra.
- MO-S (MOS-F)
MO-S is a semi-empirical program with advanced methods (configuration interactions and random phase approximation) for evaluation of UV-visible electronic absorption spectra. Use MO-S for he evaluation and interpretation of electronic structure transitions.
- Extended Hückel
Extended Hückel is a semiempirical quantum mechanical method used for calculating the electronic wavefunction to determine electron densisties, molecular orbitals, electrostatic potentials, partial charges and bond orders.
- QSAR & QSPR Module
SCIGRESS combines experimental data with over 100 descriptors to develop QSAR protocols, and additional descriptors can be defined within the system.
Computational tools interfaced to SCIGRESS: