Questions tagged [self-consistent-field]

For questions related to performing calculation using the self consistent field (SCF) algorithm, for example Hartree-Fock and Kohn-Sham Density Functional Theory.

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19 votes
3 answers

What are the types of MCSCF?

Similar to: What are the types of SCF? What are the types of Quantum Monte Carlo? What are the types of ab initio Molecular Dynamics? What are the types of pseudopotentials? What are the types of DFT?...
I have no free time anymore's user avatar
20 votes
5 answers

What are the types of SCF?

Many of us know the most common types of SCF (though we can do better than Wikipedia at explaining them): RHF (Restricted Hartree-Fock), RKS (Restricted Kohn-Sham) [link to answer] UHF (Unrestricted ...
I have no free time anymore's user avatar
15 votes
2 answers

Convergence by energy and/or density?

The SCF is an iterative procedure to produce the ground state energy and wavefunction for Hartree-Fock, MCSCF, and DFT. Due to the iteration, one needs to establish convergence criteria. Depending on ...
Tyberius's user avatar
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23 votes
4 answers

Difficult cases for converging Kohn-Sham SCF calculations

In a recent article by Woods et. al.[1] a couple of methods for converging ground-state Kohn-Sham DFT calculations are reviewed and compared. In their test suite they give plenty of examples for badly ...
Michael F. Herbst's user avatar
16 votes
1 answer

Standard values for level of convergence

In matter modelling we use self consistent approaches for calculating different properties. Many DFT codes find the ground state of the system by determining total energy self consistently. Going ...
Thomas's user avatar
  • 9,072
17 votes
3 answers

How is "basis set projection" done?

I recently came across something called the basis set projection in Q-chem's manual. What it seems to do is to take the converged SCF in a smaller basis set, and then "projects" that onto a ...
S R Maiti's user avatar
  • 6,841
12 votes
2 answers

One-center two-electron integrals between 1s STO

As per @user1271772 's suggestion I am asking this question here again. I am trying to understand SCF cycle by trying to code up solved example from Quantum Chemistry by Levine (page 443, 5th edition)...
ipcamit's user avatar
  • 545
9 votes
4 answers

What programs can do electron integrals and SCF calculations with more than one CPU?

Similar to this question which asks for each answer to provide one software that can do CASSCF: I am interested in software that can do integrals, SCF (Hartree-Fock), and the integral transformation, ...
Eugene Chybisov's user avatar
9 votes
1 answer

Should I use a lower threshold for calculations involving SOC?

I'm studying a compound $\ce{VSe_2}$ using the DFT package Quantum ESPRESSO (QE). The following is the input file. ...
Atom's user avatar
  • 945
6 votes
1 answer

How does electronic iteration work in a VASP relaxation calculation?

I am a beginner using VASP to do material modeling, and I'm confused about the following questions: How does the electronic iteration work in VASP relaxation calculation? Is the electronic iteration ...
Kevin's user avatar
  • 61
4 votes
0 answers

Interpretation of total energy in SCF calculation using Quantum Espresso [closed]

I am performing SCF calculations using Quantum Espresso for crystalline materials to determine the band gaps and energies. A sample output for one of the crystals is shown below. ...
Prashant Govindarajan's user avatar