Frequently Asked Questions

What Is PQR?

PQR is an online database of molecular properties predicted from quantum mechanics with integrated capabilities for molecular visualization and data sharing.

What Is Unique About PQR?

Based on the number of molecules, PQR is currently the largest open database of molecular quantum calculations. PQR features interactive high-quality rendering of molecular structures and properties on computers, tablets, and cell phones and allows to efficiently share data via digital object identifiers (DOI) and scannable QR barcodes.

How Does PQR Help Researchers, Educators, And Students?

PQR gives users instant access to a large database of molecular properties computed from quantum mechanics, saving on the time necessary to repeat the same calculations over and over again. Error bars for calculated properties are provided to allow users to assess the reliability of the data. We expect this to be particularly useful as a guide for non-expert users of computations and students.

PQR makes it particularly easy to share a 3D rendition of molecular structures and properties for research, collaboration, and classes. For example, research papers can link to PQR entries using digital object identifiers (DOI). Lecture slides and handouts can link to PQR using barcodes that students can scan on their mobile devices. An example use would be linking to the structures of D- and L-glucose to allow students to explore stereoisomerism interactively and in 3D.

What Molecular Properties Does PQR Currently Feature?

PQR features geometries, heats of formation, dipole moments, orbital energies, and molecular point groups. PQR renders molecular structure (CPK, vdW spheres, lines) and vdW surfaces.

How Does PQR Calculate Data?

PQR uses the PM6 semiempirical quantum chemical model as implemented in the MOPAC program package. More levels of theory are in preparation.

How Do I Access / Refer To Data on PQR?

On your computer, go to http://pqr.pitt.edu and search for a molecule or browse by tags. To create a scannable barcode linking to the molecule, click on "Create PQR barcode". The automatically generated code can be embedded in lecture slides, handouts, manuals, homework sets, etc.

Which Barcode Scanner Should I Use?

Any barcode scanner that can read 2D (QR) codes should work. We have made good experiences with "QR Reader" for iOS and "Google Goggles" for Android. Both scanners are free of charge and do not display advertisements.