Example: Multiresolution¶

Download Multiresolution_H2O.run

#! /bin/sh

# This example demonstrates how to use different levels of numerical precision
# for different regions, with the aim of increasing computational efficiency.

# Let us assume that we are interested in having an accurate description only
# for a subregion of a large chemical system (in this simple example, the
# central water molecule). The system can be divided into sub-regions and
# different levels of numerical accuracy can be used for each of these sub-
# regions.

# In this example we will tweak:
# - the basis set (Basis)
# - the numerical integration (BeckeGrid)
# - the density fitting for Coulomb potential (ZlmFit)
# - the fit-set used in the Hartree-Fock Resolution of identity (RIHartreeFock)

# Note: For the regions for which no quality has been explicitly defined
# through a QualityPerRegion keyword, the quality defined in NumericalQuality
# will be used (Normal, in this example).

\$AMSBIN/ams <<eor

System
Atoms
O    0.00000000       0.00000000       0.00000000    region=Accurate
H    0.40399229      -0.65578342       0.63241539    region=Accurate
H    0.81410032       0.55624569      -0.23129097    region=Accurate
O   -3.02535626      -0.08473104      -0.47678489
H   -2.56531481       0.62644005       0.07759386
H   -2.25289644      -0.61700366      -0.80790649
O    2.95394790      -0.54939973      -0.38206034
H    3.91427727      -0.21304908      -0.44738291
H    2.87780992      -1.13241278      -1.20853726
O   -5.95425742      -0.56764616      -0.02016682    region=Far
H   -5.26308282      -0.46969096       0.69255963    region=Far
H   -5.42117992      -0.54361203      -0.86443121    region=Far
O    6.25171470      -0.62004899      -0.03702467    region=Far
H    6.16508647      -1.38696453       0.58541903    region=Far
H    7.09161199      -0.16700550       0.23679419    region=Far
End
End

Engine Band

XC
LibXC B3LYP
End

! ========================================================
! Set different basis sets for atoms in different regions:
! ========================================================

Basis
Type DZ
Core None
PerRegion Region=Accurate Type=TZP
PerRegion Region=Far      Type=SZ
End

! =============================================================
! Set the NumerialQuality to be used for the atoms that are not
! explicitely defined through a QualityPerRegion keyword
! =============================================================

NumericalQuality Normal

! ======================
! Numerical integration:
! ======================

BeckeGrid
QualityPerRegion Region=Accurate Quality=Good
QualityPerRegion Region=Far      Quality=Basic
End

! ======================================
! Density fitting for Coulomb potential:
! ======================================

ZlmFit
QualityPerRegion Region=Accurate Quality=Good
QualityPerRegion Region=Far      Quality=Basic
End

! ============================================================
! Hartree-Fock Resolution of identity (for hybrid functionals)
! ============================================================

RIHartreeFock
QualityPerRegion Region=Accurate Quality=Good
QualityPerRegion Region=Far      Quality=Basic
End

Relativity Level=None

EndEngine

eor