Introduction

This manual explains about the first-principles program package “Superconducting-Toolkit” based on the density functional theory for superconductors. Superconducting-Toolkit constructs the gap equation

\[\begin{align} \Delta_{n {\bf k}} = -\frac{1}{2} \sum_{n' {\bf k}'} \frac{K^{el}_{n {\bf k} n' {\bf k}'} + K^{\rm el-ph}_{n {\bf k} n' {\bf k}'}}{Z_{n {\bf k}}} \frac{\Delta_{n' {\bf k}'}}{E_{n' {\bf k}'}} \tanh\left( \frac{\beta E_{n' {\bf k}'}}{2} \right) \end{align}\]

from QuantumESPRESSO outputs and obtains the superconducting gap function \(\Delta_{n {\bf k}}\) by solving this equation. This program is developed by Mitsuaki Kawamura in ISSP, Japan.