Accuracy and Efficiency¶
Given a Model Hamiltonian, the most important aspects determining the accuracy of a Band calculation are:
Also important, but to a lesser degree, are the following aspects:
Hartree–Fock Resolution of the Identity (RIHartreeFock) (only for hybrid functionals)
For Many-body-perturbation theory (MBPT) options (only for MBPT calculations)
The CPU time and memory requirements strongly depend on these options, as does the accuracy of the results.
General NumericalQuality
A simple way of tweaking the accuracy of the calculation is via the NumericalQuality key. This sets the quality of several technical aspects of a Band calculation (with the notable exception of the basis set)
NumericalQuality [Basic | Normal | Good | VeryGood | Excellent]
NumericalQuality
- Type
Multiple Choice
- Default value
Normal
- Options
[Basic, Normal, Good, VeryGood, Excellent]
- Description
Set the quality of several important technical aspects of a BAND calculation (with the notable exception of the basis set). It sets the quality of: BeckeGrid (numerical integration), ZlmFit (density fitting), KSpace (reciprocal space integration), and SoftConfinement (basis set confinement). Note: the quality defined in the block of a specific technical aspects supersedes the value defined in NumericalQuality (e.g. if I specify ‘NumericalQuality Basic’ and ‘BeckeGrid%Quality Good’, the quality of the BeckeGrid will be ‘Good’)
- Basis set
- Basis input block
- Which basis set should I use?
- Frozen core
- Available Basis Sets
- Pure STO and GTO basis sets
- More Basis input options
- Confinement of basis functions
- Manually specifying AtomTypes (expert option)
- Basis Set Superposition Error (BSSE)
- Alternative elements / Virtual crystal approximation
- K-Space
- Numerical Integration
- Density Fitting
- Hartree–Fock RI
- Self Consistent Field (SCF)
- MBPT scheme
- More Technical Settings