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Hands-on session:�DFT in molecules, Finding optimized lattice parameters and convergence testing

Abdul Muhaymin

Graduate student, MSN, Bilkent University

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Outline

  • Localized vs delocalized basis set
  • Analysis of hydrogen molecule using QE
  • Angles and dihedrals
  • Quantum dots and isolated systems

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Using QE is not a good idea!

  • Or for that matter, VASP, CASTEP are not good either.
  • Localized basis sets are far more efficient
  • For our case, it won't matter though

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H2 molecule

  • Can be done in several ways: relaxation calculation, multiple SCF calculation followed by an equation of state analysis, and lastly variable-cell calculation(!)
  • How about dissociation energy!
  • Energy of two hydrogen atoms located apart from each other should be different than the energy of a hydrogen molecule 
  • Let's work on it!

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H2O molecule

  • Bond length and bond angle

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Projected DOS

We will calculate for Silicon

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The figure shown is for Aluminum��(Taken from https://pranabdas.github.io/espresso/hands-on/pdos/)