EPR Intensity Multiplet Prediction for Interactions of Electron with Selected Nucleus/Nuclei

What is the expected EPR intensity pattern for a group of equivalent nuclei? One may use this function for a quick prediction/visualization of EPR spectrum multiplets (without a specific hyperfine splitting). Its central code (computation of binomial/multinomial coefficients) is implemented in the eval_sim_EPR_iso to provide simulations of isotropic EPR spectra. The theoretical intensities/coefficients are returned either as a vector or as a barplot using the geom_bar.

Usage

plot_eval_EPRtheo_mltiplet(nucle_us_i = "1H", I = NULL, N.nuclei = 1)

Arguments

nucle_us_i

Character string, pointing to specific nucleus/nuclei in the form like "14N" or "2H". If nucle_us_i = "1H", i.e. interaction with proton(s) is considered as default one. Based on the string, the characteristic nuclear spin quantum number I is taken from the isotopes_ds dataset. If one wants to define I in a more general way, just put the nucle_us_i = NULL and define the desired I by the corresponding argument (see below).

I

Numeric value, pointing to nuclear spin quantum number of proposed nucleus/nuclei interacting with unpaired electron. I must be specified in the form like I = 0.5 (for spin 1/2), I = 1.5 (for spin 3/2) or I = 1. The default value, I = NULL, is applied only in such case when the I is defined via the nucle_us_i argument (see above).

N.nuclei

Numeric value (integer), corresponding to number of interacting equivalent nuclei (within a group). Default: N.nuclei = 1.

Value

A list consisting of:

intensity.vec

A named vector of binomial/multinomial coefficients related to theoretical intensities of isotropic EPR spectrum when the coupling between unpaired electron and the surrounding nuclei is present. Coefficient/Vector names correspond to total spin quantum numbers (e.g. for one "14N" nucleus, the names are represented by the c("-1","0","1") vector).

plot

GGplot2 object/list as a graphical representation of the intensity.vec list component.

See also

Other Simulations and Optimization: eval_ABIC_forFit(), eval_sim_EPR_iso(), eval_sim_EPR_isoFit(), eval_sim_EPR_isoFit_space(), eval_sim_EPR_iso_combo(), optim_for_EPR_fitness(), plot_eval_RA_forFit(), quantify_EPR_Sim_series(), smooth_EPR_Spec_by_npreg()

Examples

## intensity multiplet for methyl group
## (3 x 1H equivalent nuclei)
methyl.multipl <-
  plot_eval_EPRtheo_mltiplet(
    N.nuclei = 3
  )
#
## vector of predicted
## intensities/coefficients
methyl.multipl$intensity.vec
#> -1.5 -0.5  0.5  1.5 
#>    1    3    3    1 
#
## graphical repsentation
methyl.multipl$plot

#
## intensity multiplet for 2 x 14N
## in TMPD (Wuster's blue) radical cation
tmpd.14N.multipl <-
  plot_eval_EPRtheo_mltiplet(
    I = 1,
    N.nuclei = 2
  )
#
tmpd.14N.multipl$plot