PMID- 17029485
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20070802
LR  - 20061010
IS  - 0021-9606 (Print)
IS  - 0021-9606 (Linking)
VI  - 125
IP  - 13
DP  - 2006 Oct 7
TI  - A new time evolving Gaussian series representation of the imaginary time 
      propagator.
PG  - 133502
AB  - Frantsuzov and Mandelshtam [J. Chem. Phys. 121, 9247 (2004)] have recently 
      demonstrated that a time evolving Gaussian approximation (TEGA) to the imaginary 
      time propagator exp(-betaH) is useful for numerical computations of 
      anharmonically coupled systems with many degrees of freedom. In this paper we 
      derive a new exact series representation for the imaginary time propagator whose 
      leading order term is the TEGA. One can thus use the TEGA not only as an 
      approximation but also to obtain the exact imaginary time propagator. We also 
      show how the TEGA may be generalized to provide a family of TEGA's. Finally, we 
      find that the equations of motion governing the evolution of the center and width 
      of the Gaussian may be thought of as introducing a quantum friction term to the 
      classical evolution equations.
FAU - Shao, Jiushu
AU  - Shao J
AD  - Chemical Physics Department, Weizmann Institute of Science, 76100 Rehovot, 
      Israel.
FAU - Pollak, Eli
AU  - Pollak E
LA  - eng
PT  - Journal Article
PL  - United States
TA  - J Chem Phys
JT  - The Journal of chemical physics
JID - 0375360
EDAT- 2006/10/13 09:00
MHDA- 2006/10/13 09:01
CRDT- 2006/10/13 09:00
PHST- 2006/10/13 09:00 [pubmed]
PHST- 2006/10/13 09:01 [medline]
PHST- 2006/10/13 09:00 [entrez]
AID - 10.1063/1.2207142 [doi]
PST - ppublish
SO  - J Chem Phys. 2006 Oct 7;125(13):133502. doi: 10.1063/1.2207142.