Algorithm and code development is a major part of our research. Over the years, we have developed about a dozen methods and codes. Some of them are posted as public codes, and some of them are still under developments. The methods and codes we have developed include the following:
(1) The folded spectrum method, implemented in the PEscan code;
(2) The Generalized Moments method, implemented in the PEscan code;
(3) Semiempirical pseudopotential method and the fitting program
(4) Valence Force Field atomic relaxation code for large systems
(5) Linear combination of bulk band (LCBB) method and the code for million atom nanostructure and device simulation
(6) PEtot: a plane wave pseudopotential code for DFT large scale simulations.
(7) PEtot_transport: a plane wave pseudopotential quantum transport code
(8) Charge patching method and the related packages for thousand atom nanostructure calculations without doing selfconsistent calculations.
(9) Linear scaling three dimensional fragment (LS3DF) method and code for large system (>5,000 atoms) DFT calculations on petascale computers
(10) Overlap fragment method for organic system electronic structure calculations
(11) Non adiabatic molecular dynamics (time domain simulations) methods and codes
(12) Procedures to calculate shallow impurity state binding energies
(13) Procedures to calculate the deep state non-radiative trapping.
(14) Procedures to calculate electron-phonon interactions, and the related phenomena: state hopping, electron scattering, and carrier dynamics