Molecular modelers often face the tedious task of configuring repetitive workflows for multiple molecular systems or conformations. Whether it’s optimizing several protein structures or running simulations on different conformations of a molecule, the manual setup can consume precious time and increase the likelihood of errors. The GROMACS Wizard in SAMSON offers a solution: batch computations.
Batch computation allows users to apply the same molecular dynamics (MD) workflow to numerous starting states or related systems in a structured and scalable way. This tutorial-based approach streamlines the process, enabling efficiency and error reduction for molecular modeling projects. Here’s how it works:
Why Batch Computations?
Batch computations are particularly useful when:
- You have a single molecular system but with multiple initial conformations (e.g., for Umbrella Sampling).
- You work with a set of different molecular systems that require identical parameters for simulations (e.g., a collection of proteins).
Instead of treating each system or conformation individually, batch processing consolidates these into a single project where subsequent steps like minimization, equilibration, and simulation can be launched collectively, either locally or in the cloud.
Step-by-Step for Batch Processing a Single System with Many Conformations
Let’s break down how GROMACS Wizard simplifies this:
- Load Data: Begin by uploading your trajectory (path) or set of conformations into SAMSON via
Home > File > Openor by drag-and-drop. Alternatively, generate your trajectory in SAMSON using tools such as editors like Move editors or extensions like Twister. - Set Conformations: Use the Prepare tab in the GROMACS Wizard. Select your molecular system and check the “Batch preparation” option. Then, choose either a set of conformations or a trajectory path as initial states for subprojects within the batch project. Each conformation or trajectory frame corresponds to a separate subproject.
- Specify Settings: Configure the force field, specify the solvent, add optional custom index groups (for advanced analysis), and set ions to finalize the preparation.
- Define the Periodic Box: Decide whether the box should have the same dimensions for all conformations (based on the “Box lengths” option) or vary according to each conformation (using the “Solute-box distance” option). This choice affects computational time and system scaling.
- Prepare: Once settings are configured, click Prepare to create a batch project with automatically generated subfolders for each subproject.
Clear Visual Feedback
GROMACS Wizard provides a slider tool to preview how the periodic box fits each conformation in the batch. This ensures accurate box settings and visualization of trajectory data before running simulations.
Scaling Up to Multiple Systems
Working with unrelated molecular systems? You can extend batch processing by preparing each system individually, grouping their “-prepare” folders into a batch folder, and launching subsequent steps collectively. This prevents repetitive configuration and keeps your molecular modeling workflow streamlined.
Launching Simulations
Once your batch project is prepared, proceed with minimization, equilibration, and simulation steps (e.g., energy minimization, NVT/NPT equilibration, production MD). Use the “From batch folder” option to automatically apply your workflow to the entire batch. Computations can either run locally or in the cloud, depending on your preference.
For more details, check out the original documentation page.
Note: SAMSON and all SAMSON Extensions are free for non-commercial use. Download SAMSON at https://www.samson-connect.net.