Axilrod-Teller-Muto (ATM) dispersion term#
This module provides the dispersion energy evaluation for the three-body Axilrod-Teller-Muto dispersion term.
\[\begin{split}E_\text{disp}^{(3), \text{ATM}} &=
\sum_\text{ABC} E^{\text{ABC}} f_\text{damp}\left(\overline{R}_\text{ABC}\right) \\
E^{\text{ABC}} &=
\dfrac{C^{\text{ABC}}_9
\left(3 \cos\theta_\text{A} \cos\theta_\text{B} \cos\theta_\text{C} + 1 \right)}
{\left(r_\text{AB} r_\text{BC} r_\text{AC} \right)^3} \\
f_\text{damp} &=
\dfrac{1}{1+ 6 \left(\overline{R}_\text{ABC}\right)^{-16}}\end{split}\]
- tad_dftd3.damping.atm.dispersion_atm(numbers, positions, c6, rvdw, cutoff, s9=tensor(1.), rs9=tensor(1.3333), alp=tensor(14.))[source]#
Axilrod-Teller-Muto dispersion term.
- Parameters:
numbers (Tensor) – Atomic numbers of the atoms in the system.
positions (Tensor) – Cartesian coordinates of the atoms in the system.
c6 (Tensor) – Atomic C6 dispersion coefficients.
rvdw (Tensor) – Van der Waals radii of the atoms in the system.
cutoff (Tensor) – Real-space cutoff.
s9 (Tensor, optional) – Scaling for dispersion coefficients. Defaults to 1.0.
rs9 (Tensor, optional) – Scaling for van-der-Waals radii in damping function. Defaults to 4.0/3.0.
alp (Tensor, optional) – Exponent of zero damping function. Defaults to 14.0.
- Returns:
Atom-resolved ATM dispersion energy.
- Return type:
Tensor