1. The Nuts and Bolts of First-Principles Simulation
27: Upcoming Developments and the Future for DFT
Durham, 6th-13th December 2001
CASTEP Developers’ Group with support from the ESF k Network

2. Lecture 27: Developments and the Future
Outline
Brief history of DFT
Prospects for the next 5 years
New functionality
Scientific challenges
New research fields
Beyond the next 5 years
Nuts and Bolts 2001
Lecture 27: Developments and the Future

3. Lecture 27: Developments and the Future
Brief History of DFT
1964 Hohenberg-Kohn theorem - foundation of density functional theory.
1965 Kohn-Sham equations - practical method for applying density functional theory.
THEN NOTHING until
Nuts and Bolts 2001
Lecture 27: Developments and the Future

4. Brief History of DFT (all dates are approximate)
1981 First density functional theory calculations
1985 Car-Parrinello method
1989 Conjugate gradients techniques
1991 Implementation on parallel computers
1992 Chemists begin to adopt DFT - useful GGAs
1996 Residual minimisation, DIIS, density mixing
1998 Nobel prize for chemistry awarded to Walter Kohn
Nuts and Bolts 2001
Lecture 27: Developments and the Future

5. Lecture 27: Developments and the Future
New Functionality
Linear response - relevant to many properties:
NMR
g-tensor of electron
Dielectric properties
Phonons
Born effective charges
Elastic constants
Anything that can be phrased in terms of a perturbed external potential
Nuts and Bolts 2001
Lecture 27: Developments and the Future

6. Lecture 27: Developments and the Future
New functionality
Phonons can be used to calculate vibrational free energies:
Phase stability
Crystal morphology
Defect processes
Nuts and Bolts 2001
Lecture 27: Developments and the Future

7. Lecture 27: Developments and the Future
BUT
Plane waves allow fast algorithm development. When this is combined with a modular program design built from a full specification document adding new functionality should be fast, efficient (many operations will be available already) and as painless as possible.
CASTEP should be ideal for developing new functionality, for studying novel problems and for taking to new scientific fields.
Nuts and Bolts 2001
Lecture 27: Developments and the Future

8. Scientific challenges
Finite temperatures
Free energies, entropy
Phase transitions
....
Larger systems
Embedding, QM/MM approaches, ...
Longer timescales
Complex phase spaces
Nuts and Bolts 2001
Lecture 27: Developments and the Future

9. Lecture 27: Developments and the Future
New research fields
Biology
Materials science
Nuts and Bolts 2001
Lecture 27: Developments and the Future

10. Lecture 27: Developments and the Future
Beyond the next 5 years
Linear scaling approaches
Embedding
Nuts and Bolts 2001
Lecture 27: Developments and the Future

11. Lecture 27: Developments and the Future
Thanks
Workshop organisers - Stewart Clark, Phil Lindan, Walter Temmerman
Workshop sponsors - Accelrys, ESF-STRUC Psi-k Programme
CASTEP Developers Group - Stewart Clark, Phil Hasnip, Phil Lindan, Chris Pickard, Matt Probert and Matt Segall
Nuts and Bolts 2001
Lecture 27: Developments and the Future