PMID- 20687637
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20101130
LR  - 20100806
IS  - 1089-7690 (Electronic)
IS  - 0021-9606 (Linking)
VI  - 133
IP  - 4
DP  - 2010 Jul 28
TI  - Multi-Jastrow trial wavefunctions for electronic structure calculations with 
      quantum Monte Carlo.
PG  - 044111
LID - 10.1063/1.3457364 [doi]
AB  - A new type of electronic trial wavefunction suitable for quantum Monte Carlo 
      calculations of molecular systems is presented. In contrast with the standard 
      Jastrow-Slater form built with a unique global Jastrow term, it is proposed to 
      introduce individual Jastrow factors attached to molecular orbitals. Such a form 
      is expected to be more physical since it allows to describe differently the local 
      electronic correlations associated with various molecular environments (1s-core 
      orbitals, 3d-magnetic orbitals, localized two-center sigma-orbitals, delocalized 
      pi-orbitals, atomic lone pairs, etc.). In contrast with the standard form, 
      introducing different Jastrow terms allows us to change the nodal structure of 
      the wavefunction, a point which is important in the context of building better 
      nodes for more accurate fixed-node diffusion Monte Carlo (FN-DMC) calculations. 
      Another important aspect resulting from the use of local Jastrow terms is the 
      possibility of defining and preoptimizing local and transferable correlated units 
      for building complex trial wavefunctions from simple parts. The practical aspects 
      associated with the computation of the intricate derivatives of the multi-Jastrow 
      trial function are presented in detail. Some first illustrative applications for 
      atoms of increasing size (O, S, and Cu) and for the potential energy curve and 
      spectroscopic constants of the FH molecule are presented. In the case of the 
      copper atom, the use of the multi-Jastrow form at the variational Monte Carlo 
      level has allowed us to improve significantly the value of the total ground-state 
      energy (about 75% of the correlation energy with only one determinant and three 
      atomic orbital Jastrow factors). In the case of the FH molecule (fluorine 
      hydride), it has been found that the multi-Jastrow nodes lead to an almost exact 
      FN-DMC value of the dissociation energy [D(0)=-140.7(4) kcal/mol instead of the 
      estimated nonrelativistic Born-Oppenheimer exact value of -141.1], which is not 
      the case with standard nodes, D(0)=-138.3(4) kcal/mol.
FAU - Bouabca, Thomas
AU  - Bouabca T
AD  - Laboratoire de Chimie et Physique Quantiques, CNRS UMR5626-IRSAMC et Universite 
      de Toulouse, Toulouse Cedex 31000, France.
FAU - Braida, Benoit
AU  - Braida B
FAU - Caffarel, Michel
AU  - Caffarel M
LA  - eng
PT  - Journal Article
PL  - United States
TA  - J Chem Phys
JT  - The Journal of chemical physics
JID - 0375360
EDAT- 2010/08/07 06:00
MHDA- 2010/08/07 06:01
CRDT- 2010/08/07 06:00
PHST- 2010/08/07 06:00 [entrez]
PHST- 2010/08/07 06:00 [pubmed]
PHST- 2010/08/07 06:01 [medline]
AID - 10.1063/1.3457364 [doi]
PST - ppublish
SO  - J Chem Phys. 2010 Jul 28;133(4):044111. doi: 10.1063/1.3457364.