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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. Goals.
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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
Goals • Run a basic GW/BSE calculation for a gas-phase molecule and understand the input parameters and considerations that are unique to this problems. • Calculate close to quantitatively accurate excitation energies and compare with experiment • Understand the convergence behavior of GW/BSE
Workflow for Tutorial SCF GW/BSE Espresso pw.x Espresso pp.x Epsilon Sigma Choose supercell Surface.x Kernel Absorption Espresso pw.x Espresso pp.x Summarize Eigenvectors Vacuum level shift Average.py /global/project/projectdirs/m1694/BGW-2013/7-benzene
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 BN Calculation Instructions >> 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.