As a molecular modeler, navigating complex molecular paths and finding the exact conformation nodes you need can become tedious without the right tools. Luckily, the Node Specification Language (NSL) in SAMSON provides a structured way to query and manipulate molecular paths efficiently using path attributes. In this post, we’ll explore how path attributes can help simplify your workflow.
Why Path Attributes Matter
Path attributes in NSL provide a solution for effectively querying and working with specific molecular paths. They allow molecular modelers to filter paths based on properties like the number of atoms, selection status, and more. This structured querying capability can save significant time and effort, especially when working with large molecular systems.
Key Path Attributes You Should Know
Path attributes are organized under the path attribute space, which uses p as its short name and applies exclusively to conformation nodes within a molecular model. Here’s an overview of some important path attributes:
1. name
The name attribute (short name: p.n) allows you to target paths by their names. For example:
p.n "A": Matches paths named “A”p.n "L*": Matches paths with names starting with “L”
This is particularly useful for identifying specific paths within complex molecular data.
2. numberOfAtoms
The numberOfAtoms attribute (short name: p.nat) enables modelers to filter paths based on the number of atoms they contain. For instance:
p.nat > 100: Matches paths with more than 100 atomsp.n 100:200: Matches paths with 100 to 200 atoms
Whether you’re analyzing large molecular assemblies or focusing on smaller structural features, the numberOfAtoms attribute gives you precise control over your queries.
3. selected and selectionFlag
The selected attribute identifies whether a path is currently selected. For example, use p.selected for selected paths and not p.selected for unselected ones.
The selectionFlag attribute (short name: p.sf) serves a related purpose with even more flexibility:
p.sf false: Matches paths with the selection flag set tofalsep.sf: Matches paths where the selection flag istrue
Both attributes are inherited from the broader node attribute space but offer particular utility when working with paths.
Practical Applications
Combining these attributes can streamline molecular modeling tasks like filtering selections, isolating regions of interest, and analyzing complex conformations. For example, you can write expressions such as:
p.n "Helix" and p.nat > 50: Finds paths named “Helix” with more than 50 atomsp.sf and not p.selected: Isolates flagged paths that are not currently selected
These advanced queries empower modelers to focus only on the data relevant to their analysis, removing unnecessary clutter.
Learn More
The NSL path attributes provide a robust method for querying and filtering molecular paths, helping researchers and molecular modelers work more efficiently. To unlock additional potential, take a closer look at the official documentation by visiting Path Attributes Documentation.
SAMSON and all SAMSON Extensions are free for non-commercial use. You can download SAMSON at www.samson-connect.net.