This README file was generated on 2024-04-16 by Athanassios Z. Panagiotopoulos

GENERAL INFORMATION

1. Title of Dataset: Data and Codes for Critical Properties of Short Model Chains

2. Author Information
	A. Principal Investigator Contact Information
		Name: Athanassios Z. Panagiotopoulos
		Institution: Princeton University
		Email: azp@princeton.edu

3. Funding sources: Financial support for this work was provided by the Princeton Center for Complex Materials (PCCM), a U.S. National Science Foundation Materials Research Science and Engineering Center (Award DMR-2011750).

SHARING/ACCESS INFORMATION

The simulation codes have been developed in the Panagiotopoulos research group. 

GNU General Public License v3.0

DATA & FILE OVERVIEW

The codes and data files are for grand canonical Monte Carlo simulations of linear chains, as detailed in the articles referenced under "METHODOLOGICAL INFORMATION" below. The files are as follows. 

1. Excel spreadsheet [Runs.xlsx] that provides detailed information on runs and numerical results obtained. This spreadsheets is akin to a Òlab notebookÓ and provides a roadmap to recreating data using the codes provided. Several tabs are present within the spreadsheet. 

2. Code files: linear.f90. This is in the FORTRAN 90 language and has been compiled using the gfortran GNU compiler. Instructions on compiling are included as comments within the main code. 

3. Sample input and output files: inp.txt, 10_31.txt, scr01.dat. 

METHODOLOGICAL INFORMATION

Details of the computational methodology and model are provided in the following publications:

A. Z. Panagiotopoulos, V. Wong and M. A. Floriano, "Phase equilibria of lattice polymers from histogram reweighting Monte Carlo simulations," Macromolecules, 31, 912-8 (1998). http://dx.doi.org/10.1021/ma971108a

A. Z. Panagiotopoulos, "Phase Separation and Aggregation in Multiblock Chains," J. Chem. Phys., 158, 154901 (2023).  http://dx.doi.org/10.1063/5.0146673

The overall workflow for generating data is as follows:

1. Compile the linear.f90, entropy.f90, entropy2.f90, and entropy3.f90 source code files using a FORTRAN 90 compiler on your target machine (e.g., gfortran). The entropy, entropy2, and entropy3 codes as well as their associated input and parameter files are provided in https://doi.org/10.34770/ykvp-8b36. 

2. Run the main code, using the inp1.txt input file for the desired set of conditions.

3. Combine separate runs at conditions that result in overlap in the P(N,E) distributions using the entropy code, which requires as input the file input_hs.dat. The entropy code allows for histogram reweighting at other conditions and also can compute the equation of state and coexistence curves. It does not perform a full self-consistent combination of the histograms, but is significantly faster than entropy2, which does provide a full Ferrenberg-Swedsen calculation.

4. Perform long runs near the estimated location of the critical point.

5. Run entropy followed by entropy2. Entropy2 computes the order parameter distribution function and requires file Òentr2_par.datÓfor input of parameters and ÒIsing.datÓ for reading in the universal distribution. It is important to seek conditions of T, ?, and values of s and Ncrit that result in a distribution reasonably close to the Ising before the next step.

6. Optimize the critical parameters using entropy3. This code requires file Òentr3_par.datÓ for input of parameters and ÒIsing.datÓ for reading in the universal distribution

7. If desired, obtain coexistence curves and check that the input runs are consistent with the resulting coexistence curves. Specifically, there should be no runs at metastable states, liquid at chemical potential below coexistence and vapor above coexistence. Repeat runs as necessary.