Monte Carlo Simulations with an Improved Potential Function for Cu(II)-Water Including Neighbour Ligand Corrections

1991 ◽  
Vol 46 (4) ◽  
pp. 357-362 ◽  
Author(s):  
Bernd M. Rode ◽  
Saiful M. Islam
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Potential Function ◽  
Hydration Shell ◽  
Pair Potential ◽  
Computational Effort ◽  
Direct Construction ◽  
Simple Method ◽  
Dilute Aqueous Solution ◽  
Simple Pair

Abstract Monte Carlo simulations for a Cu2+ ion in infinitely dilute aqueous solution were performed on the basis of a simple pair potential function leading to a first-shell coordination number of 8, in contrast to experimental data. A simple method was introduced therefore, which allows the direct construction of a pair potential containing the most relevant 3-body interactions by means of a correction for the nearest neighbour ligands in the ion's first hydration shell. This procedure leads to much improved results, without significant increase in computational effort during potential construction and simulation

ON THE CALCULATION OF THE HEAT CAPACITY IN PATH INTEGRAL MONTE CARLO SIMULATIONS

1992 ◽  
Vol 03 (02) ◽  
pp. 337-346 ◽  
Author(s):  
D. MARX ◽  
P. NIELABA ◽  
K. BINDER
Keyword(s):  
Heat Capacity ◽  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Path Integral ◽  
General Relation ◽  
Absolute Magnitude ◽  
Computational Effort ◽  
Imaginary Time ◽  
Time Dimension ◽  
Path Integral Monte Carlo

In Path Integral Monte Carlo simulations the systems partition function is mapped to an equivalent classical one at the expense of a temperature-dependent Hamiltonian with an additional imaginary time dimension. As a consequence the standard relation linking the heat capacity Cv to the energy fluctuations, <E2>−<E>2, which is useful in standard classical problems with temperature-independent Hamiltonian, becomes invalid. Instead, it gets replaced by the general relation [Formula: see text] for the intensive heat capacity estimator; β being the inverse temperature and the subscript P indicates the P-fold discretization in the imaginary time direction. This heatcapacity estimator has the advantage of being based directly on the energy estimatorand thus requires no extra computational effort and is suited for extensive phase diagramstudies. As an example, numerical results are presented for a two-dimensional fluid withinternal magnetic quantum degrees of freedom. We discuss in detail origin and consequences of the excess term. Due to the subtraction of two relatively large contributions ofsimilar absolute magnitude a large statistical effort would be necessary for very accurateheat capacity estimates.

scholarly journals Field gamma spectrometry, Monte Carlo simulations and potential of non-invasive measurements

2012 ◽  
Vol 39 (1) ◽  
pp. 40-47 ◽  
Author(s):  
Guillaume Guérin ◽  
Norbert Mercier
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Dose Rate ◽  
Gamma Dose ◽  
Luminescence Dating ◽  
Gamma Dose Rate ◽  
Invasive Technique ◽  
Simple Method ◽  
Dose Rates ◽  
Non Invasive

Abstract The determination of gamma dose rates is of prior importance in the field of luminescence dating methods. In situ measurements are usually performed by the insertion of dosimeters or a portable gamma spectrometer cell in sediments. In this paper, Monte-Carlo simulations using the Geant4 toolkit allow the development of a new technique of insitu gamma dose rate evaluations: a spectrometer cell is placed on the surface of sediments under excavation to acquire successive spectra as sediments are removed by excavations. The principle of this non-invasive technique is outlined and its potential is discussed, especially in the case of environments in which radioelements are heterogeneously distributed. For such cases, a simple method to reconstruct gamma dose rate values with surface measurements using an attenuator is discussed, and an estimation of errors is given for two simple cases. This technique appears to be applicable, but still needs experimental validation.

scholarly journals A simple method for implementing Monte Carlo tests

2019 ◽  
Vol 35 (3) ◽  
pp. 1373-1392 ◽  
Author(s):  
Dong Ding ◽  
Axel Gandy ◽  
Georg Hahn
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Statistical Test ◽  
Uniform Bound ◽  
Data Set ◽  
Simple Method ◽  
Practical Applications ◽  
Tuning Parameters ◽  
Sequence Method ◽  
Uniformly Bounded

Abstract We consider a statistical test whose p value can only be approximated using Monte Carlo simulations. We are interested in deciding whether the p value for an observed data set lies above or below a given threshold such as 5%. We want to ensure that the resampling risk, the probability of the (Monte Carlo) decision being different from the true decision, is uniformly bounded. This article introduces a simple open-ended method with this property, the confidence sequence method (CSM). We compare our approach to another algorithm, SIMCTEST, which also guarantees an (asymptotic) uniform bound on the resampling risk, as well as to other Monte Carlo procedures without a uniform bound. CSM is free of tuning parameters and conservative. It has the same theoretical guarantee as SIMCTEST and, in many settings, similar stopping boundaries. As it is much simpler than other methods, CSM is a useful method for practical applications.

Chloride Ion in Liquid Hydroxylamine: Pair Potential Function and Monte Carlo Simulation

1994 ◽  
Vol 49 (7-8) ◽  
pp. 797-801
Author(s):  
Pornthep Sompornpisut ◽  
Sirirat Kokpol ◽  
Bernd M. Rode
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Potential Function ◽  
Energy Surface ◽  
Pair Potential ◽  
Chloride Ion ◽  
Solvation Shell ◽  
Basis Set ◽  
Basis Set Superposition Error ◽  
Solvent Molecules

Abstract An analytical pair potential function for the Cl--NH2OH interaction energy surface has been constructed based on basis set superposition error corrected ECP/DZP ab initio calculations. The potential has been tested by Monte Carlo simulation of a solution of one chloride ion in liquid hydroxylamine at 32 °C, leading to the conclusion that under these conditions Cl-forms a solvation shell of eight solvent molecules, coordinated via OH hydrogens.

Monte Carlo simulations of the homopolypeptide pair potential of mean force

2006 ◽  
Vol 241 (1-2) ◽  
pp. 354-367 ◽  
Author(s):  
R.A. Curtis ◽  
R.S. Pophale ◽  
M.W. Deem
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Pair Potential ◽  
Potential Of Mean Force

STRUCTURAL PROPERTIES OF COPPER NANOPARTICLES: MODIFIED DIFFUSION MONTE CARLO SIMULATIONS

2006 ◽  
Vol 17 (08) ◽  
pp. 1171-1177 ◽  
Author(s):  
NAZIM DUGAN ◽  
ŞAKİR ERKOÇ
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Monte Carlo Simulations ◽  
Structural Properties ◽  
Copper Nanoparticles ◽  
Pair Potential ◽  
Diffusion Monte Carlo ◽  
Coordination Numbers ◽  
Diffusion Monte Carlo Method ◽  
Stable Structures

Brief information about nanoparticles and size dependency of their properties is given. Structural properties of copper nanoparticles, Cu n (n = 50, 100, 150) have been investigated by a modified version of diffusion Monte Carlo method, using an empirical pair potential developed and parameterized for copper. Radial distribution of atoms and the coordination numbers are investigated by the optimum geometries obtained. It has been found that stable structures of copper nanoparticles considered have compact spherical shapes.

Monte Carlo Simulations of Colloidal Pair Potential Induced by Telechelic Polymers: Statistics of Loops and Bridges

2008 ◽  
Vol 41 (19) ◽  
pp. 7219-7226 ◽  
Author(s):  
Vincent Testard ◽  
Julian Oberdisse ◽  
Christian Ligoure
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Pair Potential ◽  
Telechelic Polymers
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