Molecular modelers often need to analyze and manage specific conformations of molecular structures, especially when working with nodes that represent these conformations. Filtering through large datasets to pinpoint molecules with specific characteristics can be a time-consuming task. The Node Specification Language (NSL) in SAMSON offers powerful tools to streamline this process by leveraging conformation attributes. In this post, we will explore how conformation attributes work and how they can simplify your workflow.
What are Conformation Attributes?
Conformation attributes are part of the conformation attribute space in the Node Specification Language. These attributes allow molecular modelers to define, search, and filter specific conformations in their molecular models using custom queries. The conformation attribute space is identified with the short name co and is exclusive to nodes representing conformations. By using these attributes effectively, users can quickly match nodes based on their structural or state parameters.
The Key Attributes You Need to Know
Here are some attributes in the conformation attribute space and their applications:
name
The name attribute (co.n) lets you match conformations by name. Whether you’re managing a large set of labeled nodes or looking for a group of conformations with name patterns, this attribute is invaluable. For example:
co.n "A": Matches conformations named “A”.co.n "L*": Matches conformations whose names start with “L”.
numberOfAtoms
As the name suggests, numberOfAtoms (co.nat) is used to filter conformations based on their atom count. This can be particularly helpful in refining a selection of structures for simulations or analysis. Here are some examples:
co.nat > 100: Matches conformations with more than 100 atoms.co.nat 100:200: Matches conformations with an atom count between 100 and 200.
Why is this important? Suppose you’re preparing to simulate protein conformations – you might need to select smaller or larger molecules within a specific atom range to ensure computational efficiency.
selected and selectionFlag
The selected attribute indicates whether a conformation node is selected. For example:
co.selected: Matches selected conformations.not co.selected: Matches non-selected conformations.
The selectionFlag attribute (co.sf), inherited from the node attribute space, provides similar functionality but includes a short name. For instance:
co.sf true: Matches nodes where the selection flag is enabled.
Using Conformation Attributes to Boost Productivity
The flexibility of conformation attributes in SAMSON empowers users to save time and effort considerably. For example, if you are preparing a simulation and need to exclude smaller molecules, applying an expression like co.nat > 50 can quickly refine your selection to relevant candidates.
Additionally, combining attributes can provide even more specific queries. Consider the following example:
|
1 |
co.n "L*" and co.nat 100:200 |
This matches conformations whose names start with “L” and contain between 100 and 200 atoms, allowing precise targeting of your structures without manual filtering.
Conclusion
Understanding and utilizing conformation attributes in SAMSON can significantly simplify your molecular modeling tasks. By leveraging attributes like name, numberOfAtoms, and selected, you can refine your searches and workflows with ease, focusing on the essential aspects of your molecular design projects.
To learn more, visit the official conformation attributes documentation.
SAMSON and all SAMSON Extensions are free for non-commercial use. Download SAMSON at www.samson-connect.net.