User Tools

Site Tools


exercises:common:sgcp

This is an old revision of the document!


In this exercise, you will perform ab initio molecular dynamics using Second Generation Car-Parrinello (SGCP) molecular dynamics.

Please cite Phys. Rev. Lett. 98, 066401 , if you use this method.

Published work using SGCP method:

J. Phys. Chem. C 2018, 122, 42, 24068–24076

J. Phys. Chem. Lett. 2020, 11, 9, 3724–3730

Introduction

Second Generation CPMD (2ndG CPMD) is a molecular dynamics method that combines the efficiency of Car-Parrinello MD (CPMD) with the accuracy of Born-Oppenheimer MD (BOMD). It avoids fully self-consistent field (SCF) optimizations at each time step while enabling larger integration steps and maintaining accuracy close to BOMD.

Comparison with CPMD and BOMD

Feature CPMD BOMD SGCP
SCF at each step No Yes Partially (predictor-corrector)
Time step Small (~0.1 fs) Large (~1 fs) Large (~1–2 fs)
Conserved quantity preservation Excellent Reasonable Excellent
On Born-Oppenheimer surface Slightly above Yes Very close
Works for small-gap systems Poor Good Good

Key Idea

Goal: Retain the efficiency of CPMD while achieving BOMD-level accuracy.

- Efficiency: Large time steps ; No full SCF loops - Accuracy: Forces nearly indistinguishable from BOMD - Stability: Effective for systems with vanishing band gaps - Error Control: Controlled deviation from BO surface using adaptive correction

exercises/common/sgcp.1750300194.txt.gz · Last modified: by jglan