Computer simulation study of the. theta. -point in three dimensions. I. Self-avoiding walks on a simple cubic lattice

Journal Article · Sun Apr 15 00:00:00 EDT 1990 · Journal of Chemical Physics; (USA)

DOI:https://doi.org/10.1063/1.458548· OSTI ID:7003085

Meirovitch, H; Lim, H A ^[1]

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1. Supercomputer Computations Research Institute, Florida State University, Tallahassee, Florida 32306-4052 (USA)

Using the scanning simulation method we study the tricritical behavior at the Flory {theta}-point of self-avoiding walks (SAWs) with nearest neighbors attractions {epsilon} ({epsilon}{lt}0) on a simple cubic lattice (in the following paper we investigate tricritical trails on the same lattice). The tricritical temperature {ital T}{sub {ital t}} is {minus}{epsilon}/{ital k}{sub B}{ital T}{sub {ital t}}=0.274{plus minus}0.006 (one standard deviation). The results for the radius of gyration {ital G} and the end-to-end distance {ital R} are consistent with the theoretical prediction {nu}{sub {ital t}}=0.5 and with a logarithmic correction to scaling; the ratio {ital G}{sup 2}/{ital R}{sup 2} =0.1659{plus minus}0.0001 (calculated without taking into account correction to scaling) is only slightly smaller than the theoretical asymptotic value 1/6=0.1666.... The results for the partition function {ital Z} at {ital T}{sub {ital t}} lead to {gamma}{sub {ital t}}=1.005{plus minus}0.017 in accord with theory and to {mu}{sub {ital t}}=5.058{plus minus}0.014, where {mu}{sub {ital t}} is the growth parameter; the correction to scaling in {ital Z} is found to be relatively small. For the chain length studied the divergence of the specific heat at {ital T}{sub {ital t}} ({alpha}{sub {ital t}}{approx equal}0.3) is significantly larger than that predicted by theory, (ln {ital N}){sup 3/11} (i.e., {alpha}{sub {ital t}}=0). Also, at {ital T}{sub {ital t}} our data are affected by strong correction to scaling and are thus not consistent with the theoretical value of the crossover exponent {phi}{sub {ital t}}=0.5.

• DOE Contract Number: FC05-85ER25000
• OSTI ID: 7003085
• Journal Information: Journal of Chemical Physics; (USA), Vol. 92:8; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
POLYMERS
CONFIGURATION
CRITICAL TEMPERATURE
CHAINS
COMPUTERIZED SIMULATION
CUBIC LATTICES
DIMENSIONS
PARTITION FUNCTIONS
SPECIFIC HEAT
THEORETICAL DATA
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DATA
FUNCTIONS
INFORMATION
NUMERICAL DATA
PHYSICAL PROPERTIES
SIMULATION
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE
640302* - Atomic
Molecular & Chemical Physics- Atomic & Molecular Properties & Theory