A quantum of science

How to: Conformational search using semi-empirical GFN2-xTB

A short tutorial for using GFN2-xTB method to explore the conformational space of flexible molecules and for generating solvation structures for molecules in solvent clusters.

Let's build! Hartree-Fock code from first principles part 3

A closer look at the Roothan-Hall equations and how we should go about solving them. We construct an initial guess using the core Hamiltonian and build all the necessary components for the SCF cycle.

How to: Dispersion coefficients from TDDFT

A short example for computing dispersion coefficient of methane using TDDFT in PySCF.

Let's build! Hartree-Fock code from first principles part 4

Let's implement what we have so far and construct a full SCF cycle.

Let's build! Nudged elastic band method from first principles

The nudgen elastic band procedure is constructed to calculate the minimum energy path along two minima on a simple two dimensional potential energy surface.

Let's build! Hartree-Fock code from first principles part 1

Introduction to the diagonalization of a quantum mechanical Hamiltonian

How to: Solvation energy for ionic species using DFT

A short tutorial for how the dielectric continuum solvent models can be used to calculate the solvation free energies for different solvated (ionic) species.

Let's build! Hartree-Fock code from first principles part 2

How do get to the Roothan-Hall equations and how do we get rid of the overlap matrix?