- Density Functional Theory--Applications
Extensive work on electronic band structure on transition
metals with a view to understand experimentally measured electron
momentum density and Two photon momentum density
i.e. positron annihilation using APW, LCGO method.
The exchange correlation potentials required for LD
calculations are calculated for interacting electron gas.
- Simple Model--Atoms in Jellium
A simple physically appealing model for impurity in
simple metal. Applications to: Core level Binding energies
Auger Energies, Total energy calculations of simple solids ,
Residual resistivity, etc.
- Other Investigations:
Positron binding to atoms and negative ions,two component
density functional generalization to electron positron system
motivated by development of low energy positron beams.
F-center Positron complex: e-p bound state in the presence of
Z/r potential using explicitly correlated functions,
Generator-Coordinate method.
- Model Hamiltonian Clusters, Strongly Correlated Systems:
Extensive calculations using exact diagonalization method have
been performed with a view to understand the nature of the heavy
Fermion systems on Anderson Model.
- The Hubbard and t-J models have been investigated and some of
the issues of current interest are:
- Nature of the Normal state .
- Spin charge separation--Nature of excitations .
- Non Fermi Liquid behavior .
- Interlayer Tunneling mechanism .
- Scaler and magnetic imputity in strongly correlated 1D systems.
- Ab initio Molecular Dynamics:
State of the art Computational Physics Problem; Physics of clusters;
A state of the art program to carry out
complete Car Parrinello simulated annealing
strategy and global minimization ( Conjugate Gradient method)
along with
molecular dynamics has been developed in our laboratory. A fast version
based on 'density only' is capable of treating a few hundred
atom system.
- The applications include :
- Ground state geometries of
Li/Al binary clusters,
- Melting studies on Al13 and interaction of
small clusters on Surfaces.
- A parallel version on PARAM 9000 has also been developed.
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