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

Hyperfine coupling 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.

analysis

Perform the molecular orbital analysis of the hyperfine coupling tensor.

Input block

Short variant

Extended variant

analysis:

analyze: [analyze]

kramers-pairs: [Boolean]

xyz-values: [string]

sort: [Boolean]

sort-by: [string]

occ-threshold: [real]

vir-threshold: [real]

energy-degeneracy: [real]

output-digits: [integer]

Default

The four-component calculation
analysis:
     analyze           : none
     kramers-pairs     : True
     xyz-values        : diagonal 
     sort              : False
     occ-threshold     : 0.1
     vir-threshold     : 0.1
     energy-degeneracy : 1.0e-8
     output-digits     : 1
Calculation using the perturbation theory 
analysis:
     analyze           : none
     kramers-pairs     : False
     xyz-values        : principal
     sort              : True
     sort-by           : iso
     occ-threshold     : 0.1
     vir-threshold     : 0.1
     energy-degeneracy : 1.0e-8
     output-digits     : 1

Example

analysis:
     analyze       : MO
     sort          : False
     occ-threshold : 0.01

active-atoms

Specify atoms for the calculation of hyperfine coupling tensor.

Input line

active-atoms:
                               
                                  
[formatted-string]

Default

active-atoms: all

Example

active-atoms: H

active-atoms: 5, C, 1-3

nmm-model

Model for the magnetic moment distribution of nucleus.

Input line

nmm-model:
                               
                                  
[string]

Default

nmm-model: point

Example

nmm-model: gauss

motype

Type of molecular orbitals used to calculate the hyperfine coupling tensor.

Input line

Default

motype: canonical

Example

motype: localized

Note

Both options will give the same total hyperfine coupling tensor, but will provide different MO analysis.

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

[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
point	Point distribution of the nuclear magnetic moment.
gauss	Finite distribution of the nuclear magnetic moment.

[string]	description
canonical	Canonical molecular orbitals
localized	Localized molecular orbitals

[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).

[analyze]	description
mo	Print molecular orbital contributions to the Fermi-contact, paramagnetic spin-orbit, spin dipolar and total hyperfine coupling tensor.
none	Skip analysis.

[string]	description
principal	Transform tensor of each MO contribution to principal axes of the total hyperfine coupling tensor. As a result x, y and z components of each MO contribution directly contribute to the principal values of the total hyperfine coupling 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 hyperfine coupling 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.

Latest Posts

Webpage update

June, 2025

Program update: ReSpect 5.3.0

July, 2024

Latest Publications

X2C Hamiltonian Models in ReSpect: Bridging Accuracy and Efficiency

April, 2025

Light-induced electronic chirality in achiral molecules

March, 2025

Useful Links

Our Contacts

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

isotope

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Note

g-factor

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Note

Tip

mass

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Note

analysis

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active-atoms

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nmm-model

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motype

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Note

print-level

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Latest Posts

Webpage update

Program update: ReSpect 5.3.0

Latest Publications

X2C Hamiltonian Models in ReSpect: Bridging Accuracy and Efficiency

Light-induced electronic chirality in achiral molecules

Useful Links

Our Contacts