Computer Simulation of the Absorption of CO2 Molecules by Water Cluster: 2. The Microstructure

Abstract

The simulation of the absorption of CO 2 molecules by the (H 2 O) 10 cluster is performed by the molecular dynamics method using the modified TIP4P model of water. The detailed structure of (CO 2 ) i (H 2 O) 10 clusters ( 0 ≤ i ≤ 11 ) is analyzed by the statistic geometry method based on the construction of the Voronoi polyhedra. The obtained distributions of the geometric elements of polyhedra indicate the significant changes in the structure of a cluster after the absorption of one CO 2 molecule. Only polyhedra characterizing the structure of unstable water clusters that absorbed six or seven CO 2 molecules demonstrate a nonsphericity close to the ideal tetrahedron. Linear CO 2 molecule tends to be oriented in a cluster so that the average angle formed by this molecule and permanent dipole moments of water molecules would be equal to about 30 ° .