Practical evaluation of condensed phase quantum correlation functions: A Feynman-Kleinert variational linearized path integral method

被引:217
作者
Poulsen, JA [1 ]
Nyman, G
Rossky, PJ
机构
[1] Gothenburg Univ, S-41296 Gothenburg, Sweden
[2] Univ Texas, Dept Chem & Biochem, Inst Theoret Chem, Austin, TX 78712 USA
关键词
D O I
10.1063/1.1626631
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
We report a new method for calculating the Wigner transform of the Boltzmann operator in the canonical ensemble. The transform is accomplished by writing the Boltzmann operator in a semiharmonic form, utilizing the variational centroid effective frequencies introduced by Feynman and Kleinert (FK). The approximate many-body Wigner transformed Boltzmann operator is then utilized with a linearized path integral (LPI) representation for correlation functions. It is shown that this new FK-LPI method is capable of calculating quite accurately the short time behavior of linear and highly nonlinear correlation functions for low temperature Lennard-Jones model systems and that it is vastly superior to classical dynamics. The feasibility of the FK-LPI method for large systems is illustrated by considering a model liquid composed of 32 oxygen molecules with periodic boundary conditions. Initial conditions for molecular dynamics are obtained from its Boltzmann Wigner transform and the FK-LPI method is shown to describe correctly the zero-point motion of the liquid. The effective frequency representation of the Wigner transformed thermal density operator provides an efficient way of sampling nonclassical initial conditions for molecular-dynamics simulations more generally. Applications to vibrational energy relaxation and rate constant calculations in complex molecular systems are discussed. (C) 2003 American Institute of Physics.
引用
收藏
页码:12179 / 12193
页数:15
相关论文
共 55 条
[1]  
Allen M. P., 1987, J COMPUTER SIMULATIO, DOI DOI 10.2307/2938686
[2]  
[Anonymous], 1992, SMR
[3]   QUANTUM AND CLASSICAL RELAXATION RATES FROM CLASSICAL SIMULATIONS [J].
BADER, JS ;
BERNE, BJ .
JOURNAL OF CHEMICAL PHYSICS, 1994, 100 (11) :8359-8366
[4]   Semiclassical dynamics in up to 15 coupled vibrational degrees of freedom [J].
Brewer, ML ;
Hulme, JS ;
Manolopoulos, DE .
JOURNAL OF CHEMICAL PHYSICS, 1997, 106 (12) :4832-4839
[5]   PATH INTEGRAL APPROACH TO QUANTUM BROWNIAN-MOTION [J].
CALDEIRA, AO ;
LEGGETT, AJ .
PHYSICA A, 1983, 121 (03) :587-616
[6]   THE FORMULATION OF QUANTUM-STATISTICAL MECHANICS BASED ON THE FEYNMAN PATH CENTROID DENSITY .4. ALGORITHMS FOR CENTROID MOLECULAR-DYNAMICS [J].
CAO, JS ;
VOTH, GA .
JOURNAL OF CHEMICAL PHYSICS, 1994, 101 (07) :6168-6183
[7]   THE FORMULATION OF QUANTUM-STATISTICAL MECHANICS BASED ON THE FEYNMAN PATH CENTROID DENSITY .2. DYNAMICAL PROPERTIES [J].
CAO, JS ;
VOTH, GA .
JOURNAL OF CHEMICAL PHYSICS, 1994, 100 (07) :5106-5117
[8]   THE FORMULATION OF QUANTUM-STATISTICAL MECHANICS BASED ON THE FEYNMAN PATH CENTROID DENSITY .5. QUANTUM INSTANTANEOUS NORMAL-MODE THEORY OF LIQUIDS [J].
CAO, JS ;
VOTH, GA .
JOURNAL OF CHEMICAL PHYSICS, 1994, 101 (07) :6184-6192
[9]  
Chandler D., 1987, INTRO MODERN STAT ME
[10]   THE EFFECTIVE POTENTIAL AND EFFECTIVE HAMILTONIAN IN QUANTUM-STATISTICAL MECHANICS [J].
CUCCOLI, A ;
GIACHETTI, R ;
TOGNETTI, V ;
VAIA, R ;
VERRUCCHI, P .
JOURNAL OF PHYSICS-CONDENSED MATTER, 1995, 7 (41) :7891-7938