1.1.2. Ewald Summation

  1. Introduction

       As a classical method for calculating long-range interactions, the Ewald technique decomposes the electrostatic energy into long-range and short-range terms, by calculating two terms in the real space and the reciprocal space, respectively, which results in rapid convergence of the summation.

  2. Step-by-Step Guide

    Create a computing task following the steps below

    computational_workflow

    Fig. 1.2 computational_workflow


    • step 1. Create a new task: Enter the name and description of the computing task on the corresponding page, click the “OK” button to complete the creation of the computing task; click the “Cancel” button to clear the input content

    • step 2. Upload files: Follow the instructions on the corresponding page to upload computing input files.

      Attention:

      • Please make sure to name computing input files in English!

      • If you need to upload multiple computation input files, please compress them into a zip file and upload the zip file.

    • step 3. Set computation parameters: Set computation parameters according to the prompts on the corresponding page.

    • step 4. Set runtime parameters: Currently, no need to set runtime parameters, keep the input box at default settings.

    • step 5. Save computation task: Complete the creation of the computation task and add it to the computation project. On the redirected page, you can choose

      • Continue adding computation tasks: Add a new computation task

      • View Project: View details of the current pending computational project

  3. Parameter description

    • Input file：

      包含化合价信息的cif结构文件。示例文件

    • Computing Parameters：

      Parameter Name

      Parameter Type

      Description

      Function

      ——

      The following functions are currently supported

      • Calculate the total electrostatic energy of the structure

      • Calculate the forces acting on each atom in the structure

      • Calculate the Madelung potential of each atom in the structure

      • The Madelung constant of the computational structure (Ewald_3D only)

      • Calculate the Madelung constant of the structure (only Ewald_3D is supported)

      Method

      ——

      Currently, there are five methods available for selection:

      • Ewald_2D：

      • Ewald_3D：

      • Ewald_3DC*：

      • Ewald3DC_planar_boundary：

      • Ewald3DC_spherical_boundary：
    • Running Parameters

      Currently no need to set, keep the default settings.

      Parameter Name

      Parameter Type

      Description

      Machine Name

      String（String）

      Machine name, default is machine01

      Number of Core

      Positive integer（Int）

      Number of Compute cores, default is 1

      Number of Process

      Positive integer（Int）

      Number of Computing processes, default is 1

  4. Computational Result Files

    • out.txt: results

    • If the Function option is set to Calculate the total electrostatic energy in the structure, the forces on each atom, the Madelung constant, and the Madelung potential of each atom (only Ewald_3D is supported), an ewald.json file will also be generated