Obtain Structural Insights from Hundreds of Thousands Individual Data Sets

A knowledge-based library of intermolecular interactions, IsoStar enables you to get a more in-depth knowledge of your structure by understanding how crystal structures pack in the solid state. Physical properties are directly related to packing and intermolecular interactions.

IsoStar data is used by formulation chemists and crystallographers to determine which solid-state packing is most likely, helping with polymorph prediction and overall health check risk assessments.

Data from IsoStar is used in SuperStar for pharmacophore generation and prediction of intermolecular interactions; the Full Interaction Maps (FIMs) tool that predicts a molecule’s interaction preferences; and in Fragment Hotspots that identifies the location and quality of protein binding sites.

IsoStar provides thousands of interactive 3D scatterplots that show the probability of occurrence and spatial characteristics of interactions between pairs of chemical functional groups.


H-bonded O-H contacts around aliphatic ester groups: the majority of these bonds form to the terminal –C=O rather than the etheric C-O-C.



Contoured interaction-density plot for the distribution of carbonyl contact groups around a phenyl central group. Red denotes regions most preferred by the carbonyl O atoms.




Detailed scatterplots revealing structural insights

Each scatterplot in IsoStar has been pre-calculated by searching the CSD or PDB for nonbonded interactions between a pair of functional groups A and B. The A...B contacts are transformed so that the A groups are least-squared superimposed. The resulting scatterplot shows the experimentally observed distribution of B (the contact group) around A (the central group).

Knowledge-based data

Built on the Cambridge Structural Database (CSD) - real experimental and curated results that can be traced back to specific structures.

Wide array of groups available - highly specific targeting

Target specific questions about your structure - choose one specific chemical group.

Statistical results

View graphs of the data, understand where the result has come from.

Visual representation of interaction preferences

Easy to interpret and share to explain specific interactions.

Included in
  • CSD-Core
  • CSD-Enterprise
  • Academic Research
  • Agrochemical
  • Crystallography
  • Pharmaceutical Software
Use Cases
  • End-to-End Molecular Design
  • Search Known Small Molecules


IsoStar contains information on intermolecular interactions derived from both small-molecule crystal structures in the Cambridge Structural Database (CSD) and from protein-ligand interactions observed in the Protein Data Bank (PDB). Interaction energies, computed using intermolecular perturbation theory (IMPT), are also included for many important systems.

IsoStar information on the frequencies and directionalities of intermolecular contacts is particularly relevant to medicinal chemists interested in identifying bioisosteric replacements and to molecular modellers engaged in structure-based drug design.

Yes, but only if there’s statistically significant data.

No – you would need to go back and download the individual interactions.

Start from one group you are interested in, then select other groups and investigate how they interact with your central group.