A semiempirical potential for alkali halide diatoms with damped interactions I. Rittner potential
Xiaowei Sheng1, Kwong Tin Tang2, J Peter Toennies3
1Department of Physics, Anhui Normal University, Anhui, Wuhu 24100, China.
Physical Chemistry Chemical Physics : PCCP
|October 6, 2022
Summary
A novel semiempirical potential accurately models alkali halide diatom ground states. This potential uniquely incorporates damping for electrostatic, induction, and dispersion terms, improving realism at short distances.
Area of Science:
- Physical Chemistry
- Computational Chemistry
- Spectroscopy
Background:
- Alkali halide diatom potentials are crucial for understanding molecular interactions.
- Existing models often lack realistic short-range repulsion or damping effects.
- Accurate potentials are needed for spectroscopic and theoretical studies.
Purpose of the Study:
- To develop a new semiempirical potential for alkali halide diatom ground states.
- To incorporate damping effects in electrostatic, induction, and dispersion terms.
- To create a Rittner-type model with realistic short-range repulsion.
Main Methods:
- Developed a new semiempirical potential model for alkali halide diatom ground states (X¹Σ⁺).
- Included damping for electrostatic, induction, and long-range dispersion potential terms.
- Determined model parameters by fitting experimental data (well depth, bond distance, vibrational frequency).
Main Results:
- The new potential avoids negative singularities at short internuclear distances.
- It exhibits a realistic dependence of repulsion at short distances.
- Comparison with *ab initio* potentials for LiF, LiCl, and CsI shows good agreement.
Conclusions:
- The developed semiempirical potential provides an accurate and realistic description of alkali halide diatom ground states.
- This model overcomes limitations of previous Rittner-type potentials.
- The potential is suitable for applications requiring precise molecular interaction descriptions.
Related Concept Videos
03:51Molecular Orbital Theory II
19.6K
Molecular Orbital Energy Diagrams
19.6K
02:58Crystal Field Theory - Octahedral Complexes
27.3K
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
27.3K
02:45Alkyl Halides
17.2K
Structural Properties
Alkyl halides are halogen-substituted alkanes wherein one or more hydrogen atoms of an alkane is replaced by a halogen atom such as fluorine, chlorine, bromine, or iodine. The carbon atom in an alkyl halide is bonded to the halogen atom, which is sp3-hybridized and exhibits a tetrahedral shape.
Unlike alkyl halides, compounds in which a halogen atom is bonded to an sp2 -hybridized carbon atom of a carbon-carbon double bond (C=C) are called vinyl halides. Whereas aryl...
Alkyl halides are halogen-substituted alkanes wherein one or more hydrogen atoms of an alkane is replaced by a halogen atom such as fluorine, chlorine, bromine, or iodine. The carbon atom in an alkyl halide is bonded to the halogen atom, which is sp3-hybridized and exhibits a tetrahedral shape.
Unlike alkyl halides, compounds in which a halogen atom is bonded to an sp2 -hybridized carbon atom of a carbon-carbon double bond (C=C) are called vinyl halides. Whereas aryl...
17.2K
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
43.9K
Tetrahedral Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
43.9K
01:24Van der Waals Interactions
64.8K
Atoms and molecules interact with each other through intermolecular forces. These electrostatic forces arise from attractive or repulsive interactions between particles with permanent, partial, or temporary charges. The intermolecular forces between neutral atoms and molecules are ion–dipole, dipole–dipole, and dispersion forces, collectively known as van der Waals forces.
64.8K
01:17Factors Affecting Activity Coefficient
884
The extended Debye-Hückel equation indicates that the activity coefficient of an ion in an aqueous solution at 25°C depends on three partially interdependent properties: the ionic strength of the solution, the charge of the ion, and the ion size.
The activity coefficient value for an ion is close to one when the solution has almost zero ionic strength, i.e., when the solution shows close to ideal behavior. As the ionic strength of the solution increases from 0 to 0.1 mol/L, a...
The activity coefficient value for an ion is close to one when the solution has almost zero ionic strength, i.e., when the solution shows close to ideal behavior. As the ionic strength of the solution increases from 0 to 0.1 mol/L, a...
884