Best first run
Example 1: Protein-ligand
The shortest full demonstration of setup, production MD, ligand analysis, NETWORX output, and a final figurebook.
Best for
New users, teaching demos, environment checks, and the standard protein plus small-molecule workflow.
Files this example uses
input/CPD32_9G94.pdb
Starting protein-ligand structure
parameters/A1D.str
CGenFF stream file for A1D
parameters/A1D.cgenff.mol2
CGenFF MOL2 file for A1D
prepared_system/
Reference setup outputs
completed_run/
Reference MD and analysis outputs
Prepare a clean working copy
Run this from the PyMACS repository root. It activates the setup environment, creates a disposable run folder, and copies the required input and ligand files.
conda activate cgenff
mkdir -p RUNS/example1_beginner_test
cd RUNS/example1_beginner_test
cp ../../Example_Choices/Example1/input/CPD32_9G94.pdb .
cp ../../Example_Choices/Example1/parameters/A1D.str .
cp ../../Example_Choices/Example1/parameters/A1D.cgenff.mol2 .
Run Script 1 setup
This builds the CHARMM/CGenFF-compatible GROMACS system: cleaned coordinates, topology, box, solvent, ions, and EM input.
python ../../1_AutomateGromacs.py --pdb CPD32_9G94.pdb --ligand A1D
Run EM, NVT, NPT, and short production MD
Switch to the MD/analysis environment and run a small CPU-only test. Increase --ns later after the workflow works.
conda activate mdanalysis
python ../../2_AutomateGromacs.py --mode ligand --ligand A1D --ns 0.25 --compute CPU --headless
Analyze ligand stability and contacts
Script 3A recenters the trajectory, makes RMSD/RMSF/Rg plots, detects ligand contacts, and writes analysis tables.
python ../../3A_AutomateGromacs.py --mode ligand --ligand A1D --headless
Build networks and the figurebook
NETWORX turns contact tables into ligand-residue network figures. The PDF script packages finished plots into a review-ready report.
python ../../3B_NETWORX.py --ligand A1D
python ../../4PDF4MD.py
Beginner guardrails
- Use this example first if you are unsure where to start.
- Keep --ns 0.25 until the full command chain finishes once.
- Do not rename A1D files unless you also update every topology and command reference.