1. Tutorial: Quasiparticle and Optical Excitation Energies of the Benzene Molecule Sahar Sharifzadeh Molecular Foundry, LBNL ssharifzadeh@lbl.gov /global/project/projectdirs/m1694/BGW-2013/7-benzene

2. Goals 1.Run a basic GW/BSE calculation for a gas-phase molecule and understand the input parameters and considerations that are unique to this problems. 2.Calculate close to quantitatively accurate excitation energies and compare with experiment 3.Understand the convergence behavior of GW/BSE

3. Workflow for Tutorial SCF /global/project/projectdirs/m1694/BGW-2013/7-benzene GW/BSE Average.py Surface.x Espresso pw.x Espresso pp.x Espresso pw.x Espresso pp.x KernelAbsorption Summarize Eigenvectors EpsilonSigma Choose supercell Vacuum level shift

4. Some Hints on Benzene Isolated molecule  only k-point (0,0,0) necessary No shifted grid for Epsilon No wavefunction interpolation in BSE If having run errors, try “/bin/bash/” before starting to run Run kernel and sigma at the same time /global/project/projectdirs/m1694/BGW-2013/7-benzene >> cp -rP /project/projectdirs/m1694/BGW-2013/6-boron_nitride $SCRATCH/ Please go the directory ``6-boron_nitride/1-mf/`` Enter each directory in numerical order and follow the instructions in the README files. BN Calculation Instructions