ReSpect program

isotope

Set the isotope of the nucleus.

Input block

Extended variant

isotope:

[element-symbol]: [integer]

[element-index]: [integer]

...

Default

Isotopes with largest abundance and non-zero spin.

Example

isotope:
   N  : 15
   10 : 2

Note

The data in the isotope block is processed line by line, therefore the latter data overwrites the former one.

Isotope block is processed before g-factor and mass block, therefore the data can be overwritten by these blocks.

g-factor

Specify the nuclear g-factor.

Input block

Extended variant

g-factor:

[element-symbol]: [integer]

[element-index]: [integer]

...

Default

G-factor of isotopes with largest abundance and non-zero spin.

Example

g-factor:
   H : 5.5856947
   2 : 0.8574382
   C : 1.4048236

Note

The data in the g-factor block is processed line by line, therefore the latter data overwrites the former one.

Data from g-factor block overwrites setting from the isotope block.

Tip

nuclear spin-rotation tensor is calculated only for active atoms (non-zero g-factor). This keyword can be used to set non-zero g-factor for elements witch isotopes have only zero or unknown magnetic moment to perform hypothetical studies (like f.e. At).

mass

Set the mass of the nucleus.

Input block

Extended variant

mass:

[element-symbol]: [integer]

[element-index]: [integer]

...

Default

Mass of isotopes with largest abundance and non-zero spin.

Example

mass:
   N  : 14.0030740048
   10 : 15.0001088982

Note

The data in the mass block is processed line by line, therefore the latter data overwrites the former one.

Data from mass block overwrites setting from the isotope block.

xc

Specify details associated with the evaluation of the exchange–correlation (xc) kernel.

Input block

Short variant

xc: 
                                         
                                            
                                               
                                                
                                               
                                               
                                                  
                                                     
[functional]

Extended variant

xc:

functional: [functional]

noncollinearity: [string]

Default

xc:
  functional      : from-scf
  noncollinearity : v2005

Example

xc: XALDA

xc:
     functional      : XALDA
     noncollinearity : v2019

Warning

The use of ALDA or XALDA options is not recommended, because they usually approximate the full xc kernel. Their use is only recommended when comparing the calculated data to implementations in other quantum chemistry programs, where those approximations can not be avoided.

eri

Specify details associated with the evaluation of electron repulsion integrals (ERI) and related two-electron Fock contributions.

Input block

Extended variant

eri:

class: [string]

threshold: [real]

Default

Default is taken from the scf step of the calculation.

Example

eri:
   class:        ssss/abcd 
   threshold:    1.e-15

Note

Calculation of nuclear spin-rotation constants does not involve Coulomb contribution to the Fock matrix, therefore the calculation depends on the ri-j acceleration technique only via perturbation-free molecular orbitals.

analysis

Analyze contributions from molecular orbitals to the paramagnetic part of the nuclear spin-rotation tensor.

Input block

Short variant

Extended variant

analysis:

analyze: [analyze]

xyz-values: [string]

sort: [Boolean]

sort-by: [string]

occ-threshold: [real]

vir-threshold: [real]

energy-degeneracy: [real]

output-digits: [integer]

Default

analysis:
     analyze           : none
     xyz-values        : principal
     sort              : True
     sort-by           : iso
     occ-threshold     : 0.1
     vir-threshold     : 0.1
     energy-degeneracy : 1.0e-8
     output-digits     : 2

Example

analysis:
     analyze       : MO
     xyz-values    : diagonal
     sort          : False
     occ-threshold : 0.01
     vir-threshold : 0.01

diis

Specify setting of DIIS (direct inversion in the iterative subspace) scheme.

Input block

Short variant

Extended variant

diis:

start: [integer]

collect: [integer]

maximum: [integer]

Default

diis:
  start   : 1
  collect : 3
  maximum : 30

Example

diis: on

grid

Specify atomic grids for the numerical evaluation of exchange-correlation DFT contributions.

Input block

Short variant

Extended variant

grid:

all: [string]

[element-symbol]: [string]

[element-index]: [string]

...

Default

Grid defaults are taken from the SCF section.

Example

grid: large

grid:
     C: medium
     7: large

Note

There can be multiple instances of element-symbol and element-index in the grid block.

While lines in the grid block can be mixed, they are always processed in the following order: "all", all "element-symbol" and all "element-index" keywords.

The order of processing the data matters, since the latter lines rewrite the data of the former lines. This way one can easily set the same grid for all Carbons except the Carbon number 7 (see example).

gauge

Specify the center of rotation of the molecule.

Input line

gauge:
                               
                                  
[formatted-string]

Default

gauge: center-of-mass

Example

gauge: atom 2

gauge: coordinates-origin

active-atoms

Specify atoms for the calculation of nuclear spin-rotation tensor.

Input line

active-atoms:
                               
                                  
[formatted-string]

Default

active-atoms: all

Example

active-atoms: H

active-atoms: 5, C, 1-3

print-level

Set the amount of information printed in the output file.

Input line

print-level:
                               
                                  
[string]

Default

print-level: normal

Example

print-level: long

convergence

Convergence threshold for the self-consistent procedure.

Input line

convergence:
                               
                                  
[real]

Default

convergence: 1.0e-5

Example

convergence: 1.0e-3

dmixing

Mixing parameter for the self-consistent procedure.

Input line

Default

dmixing: 1.0e0

Example

dmixing: 0.2e0

maxiterations

Maximum number of iterations for the self-consistent procedure.

Input line

maxiterations:
                               
                                  
[integer]

Default

maxiterations: 30

Example

maxiterations: 20

[formatted-string]	description
atom [integer]	Set the center of rotation on the atom number [integer], where [integer] is the index of the atom in the molecular geometry.
coordinates-origin	Set the center of rotation on the origin of the coordinate system.
center-of-mass	Set the center of rotation on the center of mass of the system.
point [x] [y] [z]	Define the center of rotation as Cartesian coordinates in atomic units.

[formatted-string]	description
all	Select all active atoms (with non-zero g-factor).
[N], [M], ...	Specify a set of atoms separated by comma. Use either geometry index of the atom (including dash separated range) or atom label.

[string]	description
normal	Standard amount of information (recommended).
long	Additional information is printed in the .out file (may clog the output).
debug	New .dbg file will be created with even more information (mostly used for debugging purposes).
long-debug	New .dbg file will be created with potentially huge amount of information (it is feasible only for small systems).

[functional]	description
xalda	Uses SVWN5 functional for the exchange-correlation kernel, regardless of the type of the xc functional in the scf step. Full Hartree–Fock kernel is calculated with the percentage of the exchange admixture taken from the scf step.
alda	Uses SVWN5 functional for the exchange-correlation kernel, regardless of the type of the xc functional in the scf step. The Hartree–Fock exchange kernel is omitted even if the scf step was calculated using hybrid functional. Note that the Coulomb part of the Hartree–Fock kernel is not omitted. This is relevant for the open-shell calculation where Coulomb part is nonzero.
from-scf	Functional for calculation of the xc kernel matches the functional from the scf step.

[string]	description
v2005	The 2005 version of the noncollinear xc kernel has both numerical and analytical form. The numerical formulation of the xc noncollinear scheme for closed-shell reference state was for the first time presented in ref [Komorovsky2008], while its analytical formulation was presented later in ref [Komorovsky2015]. The numerical form is derived from the open-shell noncollinear xc potential which was for the first time used for the calculation of g-tensor at two-component level [Malkin2005]. The implementation details of this noncollinear xc potential can be found in reference ReSpect article [Repisky2020] in eq (68). Note that in the numerical evaluation of the xc kernel one calculates numerical derivative of the xc potential with the numerical parameter being the external magnetic field. The numerical evaluation of the xc kernel was abandoned in 2015. The implementation details of the analytical form of the 2005 version of the noncollinear xc kernel is summarized in Table III in ref [Repisky2020] labeled with superscript d. These versions of the noncollinear scheme were used in all ReSpect calculations till 2019. The notable disadvantage of the 2005 version of the noncollinear xc kernel is inconsistency of the numerical and analytical formulation discussed in ref [Repisky2020] section II.E (i.e. inconsistency of the xc potential and kernel) I. Malkin, O. L. Malkina, V. G. Malkin, and M. Kaupp, J. Chem. Phys. 123, 244103 (2005) S. Komorovsky, M. Repisky, O. L. Malkina, V. G. Malkin, I. Malkin-Ondik, and M. Kaupp, J. Chem. Phys. 128, 104101 (2008) S. Komorovsky, M. Repisky, E. Malkin, T. B. Demissie, K. Ruud, J. Chem. Theory Comput. 11, 3729–3739 (2015) M. Repisky, S. Komorovsky, M. Kadek, L. Konecny, U. Ekstrom, E. Malkin, M. Kaupp, K. Ruud, O. L. Malkina, and V. G. Malkin, J. Chem. Phys. 152, 184101 (2020)
v2019	The 2019 version of the noncollinear xc kernel for both open- and closed-shell systems have been published in the framework of LR-TDDFT [Komorovsky2019]. This is the most general formulation of the noncollinear scheme and can be used for prediction of all spectroscopic parameters available in the ReSpect. The xc potential and kernel is formulated in the analytic form. The closed-shell limit of the open-shell noncollinear scheme corresponds to the xc kernel for the first time presented in ref [Bast2009]. In the output files we refer to closed-shell formulation of the noncollinear xc scheme as WB2009 ([Wang2004] + [Bast2009]). The implementation details of the 2019 version of the noncollinear xc kernel is summarized in Table III in reference ReSpect article [Repisky2020] labeled as recommended option (superscript b). F. Wang and T. Ziegler, J. Chem. Phys. 121, 12191 (2004) R. Bast, H. J. A. Jensen, and T. Saue, Int. J. Quant. Chem. 109, 2091–2112 (2009) S. Komorovsky, P. Cherry, and M. Repisky, J. Chem. Phys. 151, 184111 (2019) M. Repisky, S. Komorovsky, M. Kadek, L. Konecny, U. Ekstrom, E. Malkin, M. Kaupp, K. Ruud, O. L. Malkina, and V. G. Malkin, J. Chem. Phys. 152, 184101 (2020)

[string]	description
llll	evaluate only the [LL\|LL] class (default for one- and two-component Hamiltonians)
ssll/abcd	evaluate exactly [LL\|LL], [LL\|SS] and [SS\|LL] classes but neglect [SS\|SS]
ssss/aabb	evaluate exactly [LL\|LL], [LL\|SS] and [SS\|LL] classes and use an one-center approximation for [SS\|SS]. In this approximation, both functions in [SS\| and \|SS] should share the same atomic center, otherwise they are excluded from evaluation. This is the default for four-component Hamiltonians.
ssss/abcd	evaluate exactly all four ERI classes

[analyze]	description
MO	Analyze molecular orbital (MO) contributions to the paramagnetic part of the nuclear spin-rotation tensor.
none	Skip analysis.

[string]	description
principal	Transform tensor of each MO contribution to principal axes of the total nuclear spin-rotation tensor. As a result x, y and z components of each MO contribution directly contribute to the principal values of the total nuclear spin-rotation tensor.
diagonal	Analyze diagonal components of the MO contribution tensor. WARNING: As a result of this analysis, x, y and z component of the MO tensor does not in general directly contribute to the principal values of the total nuclear spin-rotation tensor.

[string]	description
iso	Only contributions with the modulus of isotropic value larger then threshold are printed to output.
x	Only contributions with the modulus of x (principal) tensor component larger then threshold are printed to output.
y	Only contributions with the modulus of y (principal) tensor component larger then threshold are printed to output.
z	Only contributions with the modulus of z (principal) tensor component larger then threshold are printed to output.

[string]	description
coarse	Adaptive angular part with radial number of points calculated as 30 + (10*p), where p is the number of period of the defined element.
medium	Adaptive angular part with radial number of points calculated as 40 + (10*p), where p is the number of period of the defined element.
large	Adaptive angular part with radial number of points calculated as 50 + (10*p), where p is the number of period of the defined element.
adaptive	Adaptive grid in both the radial and angular part calculated from the input basis.

[string]	description
coarse	Adaptive angular part with radial number of points calculated as 30 + (10*p), where p is the number of period of the defined element.
medium	Adaptive angular part with radial number of points calculated as 40 + (10*p), where p is the number of period of the defined element.
large	Adaptive angular part with radial number of points calculated as 50 + (10*p), where p is the number of period of the defined element.
adaptive	Adaptive grid in both the radial and angular part calculated from the input basis.

[string]	description
coarse	Adaptive angular part with radial number of points calculated as 30 + (10*p), where p is the number of period of the defined element.
medium	Adaptive angular part with radial number of points calculated as 40 + (10*p), where p is the number of period of the defined element.
large	Adaptive angular part with radial number of points calculated as 50 + (10*p), where p is the number of period of the defined element.
adaptive	Adaptive grid in both the radial and angular part calculated from the input basis.

[string]	description
coarse	Adaptive angular part with radial number of points calculated as 30 + (10*p), where p is the number of period of the defined element.
medium	Adaptive angular part with radial number of points calculated as 40 + (10*p), where p is the number of period of the defined element.
large	Adaptive angular part with radial number of points calculated as 50 + (10*p), where p is the number of period of the defined element.
adaptive	Adaptive grid in both the radial and angular part calculated from the input basis.

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July 17, 2024

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July, 2024

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Book chapter on relativistic real-time electron dynamics

May, 2024

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May, 2024

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Department of Chemistry
UiT The Arctic University of Norway
Tromsø, NO-9037 Norway
Email: info@respectprogram.eu