Current Limitations of Density Functional Theory M Alaei

Current Limitations of Density Functional Theory M. Alaei Isfahan University of Technology

ab-initio Hamiltonian of the coupled electron-nucleus system

ab-initio Hamiltonian of the coupled electron-nucleus system

Hartee-Fock The determinat satisfies the requirement of antisymmetry. This most elementary correlation between fermions is sometimes called Pauli correlation

Post-Hartee-Fock To Include Coulomb correlation

What correlation means With correlation :

What correlation means Without correlation :

Cost of calculations Incudes DFT

DFT aim : Mapping from interacting system to non-interacting HK

DFT aim : Mapping from interacting system to non-interacting KS

DFT and literatures

How DFT works HK KS

How DFT works KS equations

s n u o e e g o LDA m o H Inho c e el s n tro ou e n e g mo s ga gas n o r t elec Exact expression for XC GGA

Success of GGA and LDA 1 - They obey some universal sum rules for XC functionals and some universal constrains like as 2 - Cancellation of local errors

…And about LDA and GGA problems

Fractional electron and DFT

Orbital density functional (EXX, OEP, LDA+U, SIC, …) Orbital density functional as a means to restore the discontinuities in the total-energy derivative and the exchange–correlation potential

Orbital density functional (LDA+U and LDA+U+DMFT) LDA+U Adding fluctuation (LDA+U+DMFT

Van der walls forces and LDA and GGA Graphene-graphene binding-energy

Van der walls forces and LDA and GGA

Solution Where : Or in mesh language :

Ju. No. Lo - Julich Non Local code www. fz-julich. de/iff/src/th 1/Ju. No. Lo

How Ju. No. Lo works Ju. No. Lo is a Post possessing code and needs only charge density In real space (In principle Ju. No. Lo should work with every DFT code) We checked Ju. No. Lo for PWscf, DACAPO, VASP and now We are checking CASTEP

Ju. No. Lo and Computer time