1. Cohesive energy of ferroelectric material BaTiO3
HF orbital
DFT/LDA orbital
DMC
31.3 +/- 0.3 eV
DMC
30.1 +/- 0.3 eV
DFT(PW-91): eV (20% off)
Exp: eV

2. CDMC for optimization of geometries
-Scan force along an energy
path
-Fit to find minimum
of force
~10x faster than
discrete sampling

3. CDMC for geometries:
optimization of ferroelectric unit cell of BaTiO3
-Fix a=4.00 angstroms
-Ti is offset ~.06 A
-ferroelectric properties are
very sensitive on accuracy
of tetragonal lattice const. c
Method c (angstroms)
DFT(LDA)
DFT(PBE) HF
DMC (1)
Exp c a