A new method is presented for the simulation of an ensemble of polymer rings of variable size at fixed monomer chemical potential. Called pivot-coupled grand canonical Monte Carlo ~PC-GCMC!, it is based on the directed addition or removal of a monomer to or from a ring, coupled to the pivot of a section of the ring to maintain the ring’s continuity. Application of PC-GCMC to single, isolated ri...

An instance of the graph-constrained max-cut (GCMC) problem consists of (i) an undirected graph G = (V,E) and (ii) edge-weights c : ( V 2 ) → R+ on a complete undirected graph. The objective is to find a subset S ⊆ V of vertices satisfying some graph-based constraint in G that maximizes the weight ∑ u∈S,v 6∈S cuv of edges in the cut (S, V \ S). The types of graph constraints we can handle inclu...

The cage occupancy of hydrogen clathrate hydrate has been examined by grand canonical Monte Carlo (GCMC) simulations for wide ranges of temperature and pressure. The simulations are carried out with a fixed number of water molecules and a fixed chemical potential of the guest species so that hydrogen molecules can be created or annihilated in the clathrate. Two types of the GCMC simulations are...

The grand canonical simulation algorithm is considered as a general methodology to sample the configuration of water molecules confined within protein environments. First, the probability distribution of the number of water molecules and their configuration in a region of interest for biochemical simulations, such as the active site of a protein, is derived by considering a finite subvolume in ...

We have developed a new grand canonical molecular dynamics (GCMD) algorithm to study microwave (MW) heating effects on competitive mixture sorption and have applied the method to methanol and benzene in silicalite zeolite. The new algorithm combines MW-driven molecular dynamics with grand canonical Monte Carlo (GCMC), the latter modeling adsorption/desorption processes. We established the valid...

We have synthesized a microporous magnetic framework that contained supertetrahedral decametallic cobalt clusters as nodes and 4-(tris(hydroxymethyl)methyl)pyridine ligands as linkers in a NaCl-like network. This complex shows canted antiferromagnetism with spin-glass behavior. After the removal of the guest molecules, the spin-canting and spin-glass behaviors are maintained. The permanent poro...