Does the 18-Electron Rule Apply to CrSi12?
Marissa Baddick Abreu1, Arthur C Reber1, Shiv N Khanna1
1Department of Physics, Virginia Commonwealth University, 1020 West Main Street, Richmond, Virginia 23284-2000, United States.
The Journal of Physical Chemistry Letters
|August 18, 2015
Summary
The stability of chromium silicide clusters (CrSi12) is re-evaluated, revealing it does not follow the 18-electron rule. Instead, its stability arises from crystal field effects, unlike the magic CrSi14 cluster.
Area of Science:
- Solid-state chemistry
- Materials science
- Quantum chemistry
Background:
- Incorporating magnetic species into silicon is crucial for advanced materials.
- The chromium silicide cluster (CrSi12) has been considered stable due to the 18-electron rule.
Purpose of the Study:
- To critically examine the bonding and stability of CrSi12.
- To investigate the electronic structure of CrSi12 and compare it with CrSi14.
Main Methods:
- Theoretical studies were employed to analyze the electronic structure.
- Valence electron counts and orbital occupations were determined.
- Crystal field theory was applied to explain bonding.
Main Results:
- CrSi12 has 16 effective valence electrons on the chromium atom.
- The 3dz(2) orbital in CrSi12 is unoccupied.
- CrSi12 stability is attributed to crystal field-like splitting of 3d orbitals.
- CrSi14 adheres to the 18-electron rule and shows magic cluster characteristics.
Conclusions:
- The 18-electron rule does not explain the stability of CrSi12.
- Crystal field effects govern the stability of CrSi12.
- CrSi14 serves as a benchmark for a stable magic cluster in this system.
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