ReSpect program

analysis

Perform the molecular orbital analysis of the g-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     : 5
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     : 5

Example

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

gauge

Options for solving the gauge origin problem.

Input line

Default

gauge: center-of-mass

Example

gauge: atom 2

gauge: point 0.1e0 0.0e0 0.0e0

motype

Type of molecular orbitals used to calculate the g-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

[gauge]	description
giao	Set the distibuted gauge origin using the GIAO approach.
atom [integer]	Set the gauge on the atom number [integer], where [integer] is the index of the atom in the molecular geometry.
coordinates-origin	Set the gauge on the origin of the coordinate system.
center-of-mass	Set the gauge on the center of mass of the system.
point [x] [y] [z]	Define the gauge as Cartesian coordinates in atomic units.

[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 spin-Zeeman, orbital-Zeeman and total g-tensor.
none	Skip analysis.

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

September, 2026

Program update: ReSpect 5.3.0

August, 2026

Latest Publications

Biquaternion algebra with bilinear multiplication: a general framework for relativistic electronic structure theory

September, 2026

RIXS spectroscopy with relativistic TDDFT

July, 2026

Useful Links

Our Contacts

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

analysis

Read more

gauge

Read more

motype

Read more

Note

print-level

Read more

Latest Posts

Webpage update

Program update: ReSpect 5.3.0

Latest Publications

Biquaternion algebra with bilinear multiplication: a general framework for relativistic electronic structure theory

RIXS spectroscopy with relativistic TDDFT

Useful Links

Our Contacts