QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: hsuya on August 9, 2020, 03:12

Title: LCAO basis set used for initialisation and projection in PlaneWave caclulator
Post by: hsuya on August 9, 2020, 03:12

I am using plane wave calculator for optimising my structure but in Pseudopotential->Basis Set in the plane wave calculator it is showing  "The LCAO basis set is used for initialization and projection". Why is it so, shouldn't it be plane wave basis set instead? I have attached a screenshot for the same.

Title: Re: LCAO basis set used for initialisation and projection in PlaneWave caclulator
Post by: Nordland on August 11, 2020, 08:44

Hi hsuya,

An DFT code (LCAO or Plane-Wave) need a initial guess for the electron density. The plane wave code uses LCAO orbitals to create a starting density for the self-consistent loop. This is what is meant by initialiation.

In addition, some post-analysis of the self-consistent state requires a projection onto atomic orbitals, and here the LCAO orbtials are used again.