Scaled spatial orientation tensors (sSOT), \(\varsigma_{L,n}^{(k)}\)

Source

Single nucleus spatial orientation tensors

First-order Nuclear shielding

void sSOT_1st_order_nuclear_shielding_tensor_components(double *restrict R_0, void *restrict R_2, const double omega_0_delta_iso_in_Hz, const double omega_0_zeta_sigma_in_Hz, const double eta, const double *Theta)

The scaled spatial orientation tensors (sSOT) from the first-order perturbation expansion of the nuclear shielding Hamiltonian, in the principal axis system (PAS), include contributions from the zeroth and second-rank irreducible tensors which follow,

\[ \left. \varsigma_{0,0}^{(\sigma)} = \omega_0\delta_\text{iso} \right\} \text{Rank-0}, \]
\[\begin{split} \left. \begin{aligned} \varsigma_{2,0}^{(\sigma)} &= -\omega_0\zeta_\sigma, \\ \varsigma_{2,\pm1}^{(\sigma)} &= 0, \\ \varsigma_{2,\pm2}^{(\sigma)} &= \frac{1}{\sqrt{6}}\omega_0 \eta_\sigma \zeta_\sigma, \end{aligned} \right\} \text{Rank-2}, \end{split}\]
where \(\sigma_\text{iso}\) is the isotropic nuclear shielding, and \(\zeta_\sigma\), \(\eta_\sigma\) are the shielding anisotropy and asymmetry parameters from the symmetric second-rank irreducible nuclear shielding tensor defined using Haeberlen convention. Here, \(\omega_0 = -\gamma_I B_0\) is the Larmor frequency where, \(\gamma_I\) and \(B_0\) are the gyromagnetic ratio of the nucleus and the magnetic flux density of the external magnetic field, respectively.

For non-zero Euler angles, \(\Theta = [\alpha, \beta, \gamma]\), Wigner rotation of \(\varsigma_{2,n}^{(\sigma)}\) is applied following,

\[ \mathcal{R'}_{2,n}^{(\sigma)}(\Theta) = \sum_{m = -2}^2 D^2_{m, n}(\Theta) \varsigma_{2,n}^{(\sigma)}, \]
where \(\mathcal{R'}_{2,n}^{(\sigma)}(\Theta)\) are the tensor components in the frame defined by the Euler angles \(\Theta\).

Note

  • The method accepts frequency physical quantities, that is, \(\omega_0\delta_\text{iso}/2\pi\) and \(\omega_0\zeta_\sigma/2\pi\), as the isotropic chemical shift and nuclear shielding anisotropy, respectively.

  • When \(\Theta = [0,0,0]\), \(\mathcal{R'}_{2,n}^{(\sigma)}(\Theta) = \varsigma_{2,n}^{(\sigma)}\) where \( n \in [-2,2]\).

  • \(\mathcal{R'}_{0,0}^{(\sigma)}(\Theta) = \varsigma_{0,0}^{(\sigma)} ~~~ \forall ~ \Theta\).

  • The method returns \(\mathcal{R'}_{0,0}^{(\sigma)}(\Theta)/2\pi\) and \(\mathcal{R'}_{2,n}^{(\sigma)}(\Theta)/2\pi\), that is, in units of frequency.

Parameters
  • R_0: A pointer to an array of length 1, where the components of the zeroth-rank irreducible tensor, \(\mathcal{R'}_{0,0}^{(\sigma)}(\Theta)/2\pi\), is stored.

  • R_2: A pointer to a complex array of length 5, where the components of the second-rank irreducible tensor, \(\mathcal{R'}_{2,n}^{(\sigma)}(\Theta)/2\pi\), is stored ordered as \(\left[\mathcal{R'}_{2,n}^{(\sigma)}(\Theta)/2\pi\right]_{n=-2}^2\).

  • omega_0_delta_iso_in_Hz: The isotropic chemical shift in Hz, \(\omega_0\sigma_\text{iso}/2\pi\).

  • omega_0_zeta_sigma_in_Hz: The shielding anisotropy in Hz, \(\omega_0\zeta_\sigma/2\pi\).

  • eta: The shielding asymmetry, \(\eta_\sigma \in [0, 1]\).

  • Theta: A pointer to an array of Euler angles, in radians, of length 3, ordered as \([\alpha, \beta, \gamma]\).

First-order Electric Quadrupole

void sSOT_1st_order_electric_quadrupole_tensor_components(void *restrict R_2, const double spin, const double Cq_in_Hz, const double eta, const double *Theta)

The scaled spatial orientation tensors (sSOT) from the first-order perturbation expansion of the electric quadrupole Hamiltonian, in the principal axis system (PAS), include contributions from the second-rank irreducible tensor which follow,

\[\begin{split} \left. \begin{aligned} \varsigma_{2,0}^{(q)} &= \frac{1}{\sqrt{6}} \omega_q, \\ \varsigma_{2,\pm1}^{(q)} &= 0, \\ \varsigma_{2,\pm2}^{(q)} &= -\frac{1}{6} \eta_q \omega_q, \end{aligned} \right\} \text{Rank-2}, \end{split}\]
where \(\omega_q = \frac{6\pi C_q}{2I(2I-1)}\) is the quadrupole splitting frequency, and \(\eta_q\) is the quadrupole asymmetry parameter. Here, \(I\) is the spin quantum number of the quadrupole nucleus, and \(C_q\) is the quadrupole coupling constant.

As before, for non-zero Euler angles, \(\Theta = [\alpha,\beta,\gamma]\), a Wigner rotation of \(\varsigma_{2,n}^{(q)}\) is applied following,

\[ \mathcal{R'}_{2,n}^{(q)}(\Theta) = \sum_{m = -2}^2 D^2_{m, n}(\Theta) \varsigma_{2,n}^{(q)}. \]
where \(\mathcal{R'}_{2,n}^{(q)}(\Theta)\) are the tensor components in the frame defined by the Euler angles \(\Theta\).

Note

  • When \(\Theta = [0,0,0]\), \(\mathcal{R'}_{2,n}^{(q)}(\Theta) = \varsigma_{2,n}^{(q)}\) where \( n \in [-2,2]\).

  • The method returns \(\mathcal{R'}_{2,0}^{(q)}(\Theta)/2\pi\), that is, in units of frequency.

Parameters
  • R_2: A pointer to a complex array of length 5, where the components of the second-rank irreducible tensor, \(\mathcal{R'}_{2,n}^{(q)}(\Theta)/2\pi\), is stored ordered as \(\left[\mathcal{R'}_{2,n}^{(q)}(\Theta)/2\pi\right]_{n=-2}^2\).

  • spin: The spin quantum number, \(I\).

  • Cq_in_Hz: The quadrupole coupling constant, \(C_q\), in Hz.

  • eta: The quadrupole asymmetry parameter, \(\eta_q \in [0, 1]\).

  • Theta: A pointer to an array of Euler angles, in radians, of length 3, ordered as \([\alpha, \beta, \gamma]\).

Second-order Electric Quadrupole

void sSOT_2nd_order_electric_quadrupole_tensor_components(double *restrict R_0, void *restrict R_2, void *restrict R_4, const double spin, const double v0_in_Hz, const double Cq_in_Hz, const double eta, const double *Theta)

The scaled spatial orientation tensors (sSOT) from the second-order perturbation expansion of the electric quadrupole Hamiltonian, in the principal axis system (PAS), include contributions from the zeroth, second, and fourth-rank irreducible tensors which follow,

\[\left. \varsigma_{0,0}^{(qq)} = \frac{\omega_q^2}{\omega_0} \frac{1}{6\sqrt{5}} \left(\frac{\eta_q^2}{3} + 1 \right) \right\} \text{Rank-0}, \]
\[\begin{split} \left. \begin{aligned} \varsigma_{2,0}^{(qq)} &= \frac{\omega_q^2}{\omega_0} \frac{\sqrt{2}}{6\sqrt{7}} \left(\frac{\eta_q^2}{3} - 1 \right), \\ \varsigma_{2,\pm1}^{(qq)} &= 0, \\ \varsigma_{2,\pm2}^{(qq)} &= -\frac{\omega_q^2}{\omega_0} \frac{1}{3\sqrt{21}} \eta_q, \end{aligned} \right\} \text{Rank-2}, \end{split}\]
\[\begin{split} \left. \begin{aligned} \varsigma_{4,0}^{(qq)} &= \frac{\omega_q^2}{\omega_0} \frac{1}{\sqrt{70}} \left(\frac{\eta_q^2}{18} + 1 \right), \\ \varsigma_{4,\pm1}^{(qq)} &= 0, \\ \varsigma_{4,\pm2}^{(qq)} &= -\frac{\omega_q^2}{\omega_0} \frac{1}{6\sqrt{7}} \eta_q, \\ \varsigma_{4,\pm3}^{(qq)} &= 0, \\ \varsigma_{4,\pm4}^{(qq)} &= \frac{\omega_q^2}{\omega_0} \frac{1}{36} \eta_q^2, \end{aligned} \right\} \text{Rank-4}, \end{split}\]
where \(\omega_q = \frac{6\pi C_q}{2I(2I-1)}\) is the quadrupole splitting frequency, \(\omega_0\) is the Larmor angular frequency, and \(\eta_q\) is the quadrupole asymmetry parameter. Here, \(I\) is the spin quantum number, and \(C_q\) is the quadrupole coupling constant.

For non-zero Euler angles, \(\Theta = [\alpha,\beta,\gamma]\), Wigner rotation of \(\varsigma_{2,n}^{(qq)}\) and \(\varsigma_{4,n}^{(qq)}\) are applied following,

\[\begin{split} \mathcal{R'}_{2,n}^{(qq)}(\Theta) &= \sum_{m = -2}^2 D^2_{m, n}(\Theta) \varsigma_{2,n}^{(qq)}, \\ \mathcal{R'}_{4,n}^{(qq)}(\Theta) &= \sum_{m = -4}^4 D^4_{m, n}(\Theta) \varsigma_{4,n}^{(qq)}, \end{split}\]
where \(\mathcal{R'}_{2,n}^{(qq)}(\Theta)\) and \(\mathcal{R'}_{4,n}^{(qq)}(\Theta)\) are the second and fourth-rank tensor components in the frame defined by the Euler angles \(\Theta\), respectively.

Note

  • When \(\Theta = [0,0,0]\), \(\mathcal{R'}_{2,n}^{(qq)}(\Theta) = \varsigma_{2,n}^{(qq)}\) where \( n \in [-2,2]\).

  • When \(\Theta = [0,0,0]\), \(\mathcal{R'}_{4,n}^{(qq)}(\Theta) = \varsigma_{4,n}^{(qq)}\) where \( n \in [-4,4]\).

  • \(\mathcal{R'}_{0,0}^{(qq)}(\Theta) = \varsigma_{0,0}^{(qq)} ~~~ \forall ~ \Theta\).

  • The method returns \(\mathcal{R'}_{0,0}^{(qq)}(\Theta)/2\pi\), \(\mathcal{R'}_{2,n}^{(qq)}(\Theta)/2\pi\), and \(\mathcal{R'}_{4,n}^{(qq)}(\Theta)/2\pi\), that is, in units of frequency.

Parameters
  • R_0: A pointer to an array of length 1 where the zeroth-rank irreducible tensor, \(\mathcal{R'}_{0,0}^{(qq)}(\Theta)/2\pi\), will be stored.

  • R_2: A pointer to a complex array of length 5 where the second-rank irreducible tensor, \(\mathcal{R'}_{2,n}^{(qq)}(\Theta)/2\pi\), will be stored ordered according to \(\left[\mathcal{R'}_{2,n}^{(qq)}(\Theta)/2\pi\right]_{n=-2}^2\).

  • R_4: A pointer to a complex array of length 9 where the fourth-rank irreducible tensor, \(\mathcal{R'}_{4,n}^{(qq)}(\Theta)/2\pi\), will be stored ordered according to \(\left[\mathcal{R'}_{4,n}^{(qq)}(\Theta)/2\pi\right]_{n=-4}^4\).

  • spin: The spin quantum number, \(I\).

  • v0_in_Hz: The Larmor frequency, \(\omega_0/2\pi\), in Hz.

  • Cq_in_Hz: The quadrupole coupling constant, \(C_q\), in Hz.

  • eta: The quadrupole asymmetry parameter, \(\eta_q \in [0, 1]\).

  • Theta: A pointer to an array of Euler angles, in radians, of length 3, ordered as \([\alpha, \beta, \gamma]\).

First-order J-coupling (weak coupling limit)

void sSOT_1st_order_weakly_coupled_J_tensor_components(double *restrict R_0, void *restrict R_2, const double J_iso_in_Hz, const double J_aniso_in_Hz, const double J_eta, const double *Theta)

The scaled spatial orientation tensors (sSOT) from the first-order perturbation expansion of the \(J\)-coupling Hamiltonian under weak-coupling limit, in the principal axis system (PAS), include contributions from the zeroth and second-rank irreducible tensors which follow,

\[ \left. \varsigma_{0,0}^{(J)} = 2\pi J_\text{iso} \right\} \text{Rank-0}, \]
\[\begin{split} \left. \begin{aligned} \varsigma_{2,0}^{(J)} &= 2 \pi \zeta_J, \\ \varsigma_{2,\pm1}^{(J)} &= 0, \\ \varsigma_{2,\pm2}^{(J)} &= 2\pi \frac{1}{\sqrt{6}} \eta_J \zeta_J, \end{aligned} \right\} \text{Rank-2}, \end{split}\]
where \(J_\text{iso}\) is the isotropic \(J\)-coupling, and \(\zeta_J\), \(\eta_J\) are the \(J\)-coupling tensor anisotropy and asymmetry parameters from the symmetric second-rank irreducible \(J\) tensor, defined using Haeberlen convention.

For non-zero Euler angles, \(\Theta = [\alpha, \beta, \gamma]\), Wigner rotation of \(\varsigma_{2,n}^{(J)}\) is applied following,

\[ \mathcal{R'}_{2,n}^{(J)}(\Theta) = \sum_{m = -2}^2 D^2_{m, n}(\Theta) \varsigma_{2,n}^{(J)}, \]
where \(\mathcal{R'}_{2,n}^{(J)}(\Theta)\) are the tensor components in the frame defined by the Euler angles, \(\Theta\).

Note

  • When \(\Theta = [0,0,0]\), \(\mathcal{R'}_{2,n}^{(J)}(\Theta) = \varsigma_{2,n}^{(J)}\) where \( n \in [-2,2]\).

  • \(\mathcal{R'}_{0,0}^{(J)}(\Theta) = \varsigma_{0,0}^{(J)} ~~~ \forall ~ \Theta\).

  • The method returns \(\mathcal{R'}_{0,0}^{(J)}(\Theta)/2\pi\) and \(\mathcal{R'}_{2,n}^{(J)}(\Theta)/2\pi\), that is, in units of frequency.

Parameters
  • R_0: A pointer to an array of length 1, where the zeroth-rank irreducible tensor, \(\mathcal{R'}_{0,0}^{(J)}(\Theta)/2\pi\), is stored.

  • R_2: A pointer to a complex array of length 5, where the second-rank irreducible tensor, \(\mathcal{R'}_{2,n}^{(J)}(\Theta)/2\pi\), is stored ordered as \(\left[\mathcal{R'}_{2,n}^{(J)}(\Theta)/2\pi\right]_{n=-2}^2\).

  • J_iso_in_Hz: The isotropic \(J\)-coupling, \(J_\text{iso}\), in Hz.

  • J_aniso_in_Hz: The \(J\)-coupling anisotropy, \(\zeta_J\), in Hz.

  • J_eta: The \(J\)-coupling asymmetry, \(\eta_J \in [0, 1]\).

  • Theta: A pointer to an array of Euler angles, in radians, of length 3, ordered as \([\alpha, \beta, \gamma]\).

First-order dipolar-coupling (weak coupling limit)

void sSOT_1st_order_weakly_coupled_dipolar_tensor_components(void *restrict R_2, const double D_in_Hz, const double *Theta)

The scaled spatial orientation tensors (sSOT) from the first-order perturbation expansion of the dipolar-coupling Hamiltonian under weak-coupling limit, in the principal axis system (PAS), include contributions from the second-rank irreducible tensors which follow,

\[\begin{split} \left. \begin{aligned} \varsigma_{2,0}^{(d)} &= 4\pi D, \\ \varsigma_{2,\pm1}^{(d)} &= 0, \\ \varsigma_{2,\pm2}^{(d)} &= 0, \end{aligned} \right\} \text{Rank-2}, \end{split}\]
where \(D\) is the dipolar-coupling.

For non-zero Euler angles, \(\Theta = [\alpha, \beta, \gamma]\), Wigner rotation of \(\varsigma_{2,n}^{(d)}\) is applied following,

\[ \mathcal{R'}_{2,n}^{(d)}(\Theta) = \sum_{m = -2}^2 D^2_{m, n}(\Theta) \varsigma_{2,n}^{(d)}, \]
where \(\mathcal{R'}_{2,n}^{(d)}(\Theta)\) are the tensor components in the frame defined by the Euler angles, \(\Theta\).

Note

  • When \(\Theta = [0,0,0]\), \(\mathcal{R'}_{2,n}^{(d)}(\Theta) = \varsigma_{2,n}^{(d)}\) where \( n \in [-2,2]\).

  • The method returns \(\mathcal{R'}_{2,n}^{(d)}(\Theta)/2\pi\), that is, in units of frequency.

Parameters
  • R_2: A pointer to a complex array of length 5, where the second-rank irreducible tensor, \(\mathcal{R'}_{2,n}^{(d)}(\Theta)/2\pi\), is stored ordered as \(\left[\mathcal{R'}_{2,n}^{(d)}(\Theta)/2\pi\right]_{n=-2}^2\).

  • D_in_Hz: The dipolar coupling, \(D\), in Hz.

  • Theta: A pointer to an array of Euler angles, in radians, of length 3, ordered as \([\alpha, \beta, \gamma]\).