Tutorials

This tutorial will focus on how we can determine the vibrational properties of molecules with PWscf and Quantum-ESPRESSO using the phonon code. Before we proceed, you’ll need to make sure you have the ph.

As a continuation of the previous tutorial, I will show you a few more things you can do with VMD along with some tricks for PyMOL. We’ll use a model for the phosphopantetheine tether of acyl carrier proteins.

While XCrysden is a great tool for checking your PWscf input for bugs, visualizing NEB pathways and charge densities, this tutorial will show you how VMD can provide powerful tools for visualizing results as well.

Periodic systems have always been the primary application for DFT+U. The original utility of DFT+U was largely observed in improving descriptions of band gaps and recovering insulating behavior in materials that standard approximations to DFT make metallic.

Multiple low-lying electronic states are common for open-shell transition metal complexes and other small molecules. It is important to make sure you can straightforwardly characterize each state you converge to in order to be certain you are obtaining the properties you wish to calculate.

Thus far, I’ve told you about how to calculate the Hubbard U for single sitesor multiple sites and how to troubleshoot common problems with DFT+U. In fact, calculating U is nearly as easy as carrying out a single point calculation.

Thus far, I have introduced how to calculate U from linear-response for both single-site and multiple-site systems. However, there are a few practical issues you may run into when using DFT+U to study your system.

Open shell species of any kind may have a number of different low-lying electronic states that are all self-consistent solutions. Even though DFT is a ground state method, it may be applied directly to the lowest electronic state with well-defined quantum numbers, i.

The nudged elastic band approach for identifying transition-states is implemented in Quantum-ESPRESSO and in version, 4.3.1, it can be driven by electronic structure results from either CP or PWscf. A basic example of how to use this approach is provided in #17 of the examples that are distributed with the code.

Have you ever run a relaxation or a path optimization technique (e.g. nudged elastic band or string metadynamics) on an isolated system only to find that you were getting spurious answers arising from rotation or translation of your system?