IGMPlot

IGMPlot analyzes and quantifies molecular interactions by applying the independent gradient model (IGM) and the local descriptor δg to gradients of electron density (ED) to identify and characterize interaction regions.

Key Features:

• Interaction probing and quantification: Probes and quantifies interactions between specified molecular fragments using IGM-derived descriptors.
• Local descriptor δg calculation: Computes the local descriptor δg from the independent gradient model to characterize interaction regions in terms of electron density gradient.
• Interbond Strength Index (IBSI): Calculates the interbond strength index (IBSI) as a quantitative measure of bond strength.
• Atomic contribution estimation: Estimates atomic contributions to intermolecular and interfragment interactions.
• Data preparation for visualization: Produces data for constructing 2D and 3D representations of interaction regions.
• Critical point analysis of electron density (ED): Identifies and analyzes critical points in the electron density relevant to chemical interactions.
• Electron density asymmetry assessment (PDA): Assesses asymmetry of electron density in bonds via PDA.
• Enhanced descriptor qg: Provides an enhanced descriptor qg to complement δg for finer interaction characterization.

Scientific Applications:

• Bond strength analysis: Quantitative evaluation of bond strength using IBSI and electron density descriptors.
• Electron density distribution studies: Analysis of electron density gradients and asymmetry (PDA) in intra- and intermolecular bonds.
• Interaction region identification and visualization: Identification and 2D/3D visualization of intermolecular and interfragment interaction regions.
• Atomic-level interaction decomposition: Decomposition of interactions into atomic contributions to elucidate atomic roles in binding.
• Theoretical interpretation of interaction mechanisms: Use of IGM, δg, qg, and IBSI to support theoretical analyses of molecular interaction mechanisms.

Methodology:

Uses the independent gradient model (IGM) to analyze gradients of electron density (ED) and compute the local descriptor δg; performs critical point analysis of ED, calculates IBSI, evaluates electron density asymmetry via PDA, includes the enhanced descriptor qg, and is implemented in C++.