Multiwfn Agent

Expert agent for wavefunction analysis and quantum chemistry post-processing using Multiwfn.

Overview
Capabilities
Available Tools
Workflow
Example Prompts
Configuration
See Also

Overview

The Multiwfn Agent specializes in wavefunction analysis and electronic structure post-processing. It analyzes ORCA output files to extract orbital energies, electron density information, population analysis, and generates visualizations.

Expertise Areas

Wavefunction analysis using Multiwfn
Orbital energies (HOMO/LUMO) and orbital analysis
Electron density analysis (AIM, ELF, LOL)
Population analysis (Mulliken, Hirshfeld, ADCH, RESP)
Orbital visualization and composition
Bond and interaction analysis
Spectral simulation

MCP Server

The Multiwfn Agent connects to the OHMind-Multiwfn MCP server for tool access.

Important Note

The Multiwfn Agent analyzes results from QM calculations. It requires wavefunction files (.out, .gbw) generated by the QM Agent.

Capabilities

Capability	Description
Orbital Analysis	HOMO/LUMO energies, compositions, properties
Wavefunction Analysis	General wavefunction diagnostics
Population Analysis	Various charge schemes
Electron Density	AIM, ELF, LOL, Laplacian analysis
Bond Analysis	Bond orders and strength descriptors
Weak Interactions	RDG, NCI, IGMH, IRI analyses
Aromaticity	NICS and related indices
Spectrum Simulation	UV-Vis, IR, Raman, NMR, ECD, VCD
Orbital Visualization	2D slices and 3D renders

Available Tools

Core Analysis Tools

`orbital_analysis`

Analyze HOMO, LUMO, and other molecular orbitals.

Parameters:

input_file (str): Path to .out or .gbw file, OR results_directory from ORCA
orbital_number (str): "HOMO", "LUMO", "HOMO-1", "LUMO+1", or integer
composition_method (str): "Mulliken" (default), "Hirshfeld", "NAO", "Becke"

Returns: Orbital energies, compositions, and properties

Example:

# Analyze LUMO from ORCA results
orbital_analysis(
    input_file="/OHMind_workspace/ORCA/results",
    orbital_number="LUMO",
    composition_method="Mulliken"
)

`analyze_wavefunction`

Basic wavefunction analysis for a given input file.

Parameters:

input_file (str): Path to wavefunction file (fchk/wfn/gbw)

Returns: Wavefunction diagnostics and summary

`population_analysis`

Calculate atomic charges using various methods.

Parameters:

input_file (str): Path to wavefunction file
methods (list): Charge methods to use
- "mulliken" - Mulliken population analysis
- "hirshfeld" - Hirshfeld charges
- "adch" - ADCH charges
- "resp" - RESP charges
- "cm5" - CM5 charges
- "mbis" - MBIS charges

Returns: Charges per atom for each method

`electron_density_analysis`

Analyze electron density using various methods.

Parameters:

input_file (str): Path to wavefunction file
analysis_type (str): "aim", "elf", "lol", "laplacian"

Returns: Electron density analysis results

`bond_analysis`

Analyze chemical bonds and bond orders.

Parameters:

input_file (str): Path to wavefunction file
bond_order_type (str): "mayer", "wiberg", "fuzzy"

Returns: Bond orders and strength descriptors

Interaction Analysis Tools

`weak_interaction_analysis`

Analyze noncovalent interactions.

Parameters:

input_file (str): Path to wavefunction file
analysis_type (str): "rdg", "nci", "igmh", "iri"

Returns: Weak interaction analysis results

`aromaticity_analysis`

Calculate aromaticity indices.

Parameters:

input_file (str): Path to wavefunction file
ring_atoms (list): Atom indices defining the ring

Returns: NICS values and related aromaticity measures

`energy_decomposition`

Energy decomposition analysis.

Parameters:

input_file (str): Path to wavefunction file
method (str): "lmo-eda", "sapt"

Returns: Energy decomposition results

Spectrum Simulation Tools

`simulate_spectrum`

Simulate various spectra from computed properties.

Parameters:

input_file (str): Path to wavefunction/output file
spectrum_type (str): "uv-vis", "ir", "raman", "nmr", "ecd", "vcd"
broadening (float): Peak broadening parameter

Returns: Simulated spectrum data

Visualization Tools

`generate_cube_files`

Generate cube files for densities and orbitals.

Parameters:

input_file (str): Path to wavefunction file
property (str): Property to generate ("density", "orbital", "elf", etc.)
orbital_number (int, optional): Orbital index for orbital cubes

Returns: Path to generated cube file

`visualize_orbitals`

High-level orbital visualization orchestration.

Parameters:

input_file (str): Path to wavefunction file
orbitals (list): Orbital numbers to visualize
output_format (str): Output format ("png", "cube")

Returns: Paths to visualization files

`quick_visualize_homo_lumo`

Convenience tool to quickly visualize HOMO/LUMO.

Parameters:

input_file (str): Path to wavefunction file

Returns: HOMO and LUMO visualization files

`render_orbitals_2d`

2D slice plotting of orbitals/densities.

Parameters:

cube_file (str): Path to cube file
plane (str): Slice plane ("xy", "xz", "yz")
slice_position (float): Position along perpendicular axis

Returns: 2D plot image

`render_orbitals_3d`

3D orbital rendering with VMD/Tachyon style.

Parameters:

cube_file (str): Path to cube file
isovalue (float): Isosurface value
style (str): Rendering style

Returns: 3D render image

MD Analysis Tools

`md_analysis`

Post-processing of MD trajectories.

Parameters:

trajectory (str): Path to trajectory file
topology (str): Path to topology file
analysis_type (str): "rdf", "coordination", "hbond"

Returns: MD analysis results

Advanced Analysis Tools

`adndp_analysis`

Adaptive Natural Density Partitioning analysis.

Parameters:

input_file (str): Path to wavefunction file

Returns: AdNDP bonding analysis

Workflow

Typical Analysis Workflow

graph TD
    A[QM Calculation Complete] --> B[Get results_directory]
    B --> C{Analysis Type}
    C --> |Orbital Energies| D[orbital_analysis]
    C --> |Charges| E[population_analysis]
    C --> |Bonding| F[bond_analysis]
    C --> |Visualization| G[visualize_orbitals]
    D --> H[Interpret Results]
    E --> H
    F --> H
    G --> H

Finding ORCA Files

The Multiwfn Agent can locate ORCA output files automatically:

If the QM Agent mentioned a results_directory path, use that as input_file
The tool will automatically find single_point.out or single_point.gbw in that directory
The workspace is typically: $OHMind_workspace/ORCA or $QM_WORK_DIR

Multi-Turn Tool Calling

The Multiwfn Agent supports iterative tool calling (up to 5 iterations) to handle complex analysis workflows.

Example Prompts

Charge and Reactive Hot-Spot Analysis

For the optimized cation geometry from my QM calculation (assume I have 
already generated a suitable wavefunction file), use your Multiwfn tools 
to analyze charge distribution and identify likely degradation hot spots 
under alkaline conditions.

Report which atoms or fragments are most positively charged or otherwise reactive.

Orbital Visualization

Starting from the wavefunction of a candidate cation, generate HOMO and 
LUMO visualizations (both 2D slices and 3D renders).

Describe where the LUMO is localized and what that suggests about 
degradation pathways.

HOMO/LUMO Energy Analysis

For the ORCA calculation results in /OHMind_workspace/ORCA, analyze the 
HOMO and LUMO energies using Mulliken composition analysis.

Report the orbital energies in eV and explain what the HOMO-LUMO gap 
implies for the molecule's reactivity.

Spectrum Simulation from MD Snapshot

Take a representative structure from an MD snapshot of my membrane system 
and use Multiwfn to simulate an approximate UV-Vis or IR spectrum, 
highlighting features that correlate with specific structural motifs.

Comprehensive Electronic Analysis

Using your Multiwfn tools, perform a comprehensive electronic analysis 
of this cation:

1) Calculate Hirshfeld and ADCH charges
2) Analyze the LUMO orbital composition
3) Identify any weak interactions using NCI analysis
4) Generate a 3D visualization of the LUMO

Summarize which parts of the molecule are most vulnerable to nucleophilic attack.

Configuration

Environment Variables

Variable	Purpose	Default
`MULTIWFN_PATH`	Path to Multiwfn executable	Required
`MULTIWFN_WORK_DIR`	Working directory	`$OHMind_workspace/Multiwfn`
`QM_WORK_DIR`	QM results directory	`$OHMind_workspace/ORCA`

Results Storage

Multiwfn results are saved to:

$MULTIWFN_WORK_DIR/
├── <job-name>/
│   ├── input.*           # Input files
│   ├── analysis.log      # Analysis log
│   ├── *.dat             # Data files
│   ├── *.cube            # Cube files
│   └── *.png             # Visualization images

Visualization Output

Cube files can be visualized with external tools:

VMD (Visual Molecular Dynamics)
PyMOL
Avogadro
Custom Python scripts with matplotlib

Multiwfn Agent

Table of Contents

Overview

Expertise Areas

MCP Server

Important Note

Capabilities

Available Tools

Core Analysis Tools

orbital_analysis

analyze_wavefunction

population_analysis

electron_density_analysis

bond_analysis

Interaction Analysis Tools

weak_interaction_analysis

aromaticity_analysis

energy_decomposition

Spectrum Simulation Tools

simulate_spectrum

Visualization Tools

generate_cube_files

visualize_orbitals

quick_visualize_homo_lumo

render_orbitals_2d

render_orbitals_3d

MD Analysis Tools

md_analysis

Advanced Analysis Tools

adndp_analysis

Workflow

Typical Analysis Workflow

Finding ORCA Files

Multi-Turn Tool Calling

Example Prompts

Charge and Reactive Hot-Spot Analysis

Orbital Visualization

HOMO/LUMO Energy Analysis

Spectrum Simulation from MD Snapshot

Comprehensive Electronic Analysis

Configuration

Environment Variables

Results Storage

Visualization Output

See Also

`orbital_analysis`

`analyze_wavefunction`

`population_analysis`

`electron_density_analysis`

`bond_analysis`

`weak_interaction_analysis`

`aromaticity_analysis`

`energy_decomposition`

`simulate_spectrum`

`generate_cube_files`

`visualize_orbitals`

`quick_visualize_homo_lumo`

`render_orbitals_2d`

`render_orbitals_3d`

`md_analysis`

`adndp_analysis`