MOLDEN

MOLDEN processes and visualizes molecular electronic structure and related properties from computational chemistry program outputs to support analysis of reaction pathways and molecular vibrations.

Key Features:

• Interfacing Capabilities: Pre- and postprocessing of computational chemistry program data with direct integration of GAMESS-US/UK, Gaussian, and MOPAC outputs.
• Visualization Options: Visualization of Molecular Density (MOLDEN) including molecular orbitals, electron density, molecular minus atomic density, and the Laplacian of the electron density.
• Density Display: Display of difference densities using spherically averaged atomic density or oriented ground state atomic density across several standard basis sets.
• Electrostatic Potential Calculation: Calculation of quantum mechanical electrostatic potentials and distributed multipole expansion-derived electrostatic potentials with options to fit atomic charges to these potentials on Connolly surfaces.
• Reaction Pathways and Vibrations Visualization: Visualization of reaction pathways and molecular vibrations for analysis of dynamic molecular processes.
• Structure Generation: Integrated Z-matrix editor to generate input structures for computational calculations.
• Graphics Support: Support for graphics languages and formats including XWindows, PostScript, VRML, and POV-Ray.

Scientific Applications:

• Electronic Structure Analysis: Analysis and visualization of molecular orbitals, electron densities, and their Laplacians to study electronic structure.
• Reaction Pathway and Vibrational Studies: Simulation and visualization of reaction pathways and molecular vibrations to investigate dynamic chemical processes.
• Electrostatic and Charge Analysis: Computation of electrostatic potentials and fitting of atomic charges on Connolly surfaces for charge distribution studies.
• Density and Basis-Set Comparisons: Comparison of molecular minus atomic densities and density-derived properties across standard basis sets.

Methodology:

Performs pre- and postprocessing of outputs from computational chemistry programs (GAMESS-US/UK, Gaussian, MOPAC), processing some molecular properties directly from those outputs while computing others internally before display.