Gibbs Project

Model database

Contents

• NaCl (PRH)
• Cl₂(DLJ)
• CO₂(EPM2)
• H₂O (SPC/SPCE)
• CH₃OH (L1)
• Group mass

Further details can be obtained from the according documentations.

NaCl (PRH)

Each bead (Na+ and Cl-) is modeled by a combination of Lennard-Jones and Coulomb potential.

Na+: eps/kb(K) = 43.023, sigma(A) = 2.73, q(e) = 1

Cl-: eps/kb(K) = 20.208, sigma(A) = 4.86, q(e) = -1

The cross parameters are calculated using Kong's combining rules. They lead to the following corrections of the Lorentz-Berthelot combining rules:

Ref.: Pálinkás et al., Z. Naturforsch., 32a, 1137 (1977)

Cl₂ (DLJ)

Clorine is modeled as a molecule composed of two LJ beads in the distance L.

Cl₂ : eps/kb(K) = 178.3 K, sigma(A) = 3.332, L = 0.63*sigma

Ref.: G. Galassi and D.J. Tildesley, Molecular Simulation, 13, (1994) 11

Carbon dioxide is modeled as a linear molecule consisting of three charged LJ-beads.

O: eps/kb(K) = 80.507, sigma(A) = 3.033, q(e) = -0.3256, L = 0.758*sigma

C: eps/kb(K) = 28.129, sigma(A) = 2.757, q(e) = 0.6512

Ref.: J.G. Harris and K.H. Yung, J. Phys. Chem., 99, (1995) 12021

Water is modeled by a central charged LJ bead representing oxygen and two charges for hydrogen in a distance r separated by the angle alpha.

r(A) = 1.0, alpha(o) = 109.47

O: eps/kb(K) = 78.197, sigma(A) = 3.166, q(e) = -0.82 (SPC), -0.8476 (SPCE)

H: q(e) = 0.41 (SPC), q(e) = 0.4238 (SPCE)

Ref.: Berendsen et al., in Intermolecular Forces (ed. B. Pullmann), 331-342

CH₃OH (L1)

Methanol is divided in the groups CH₃, O, and H. Oxygen is represented by a central charged LJ bead, the methyl group by a charged LJ bead in the distance r1 and by a charge for hydrogen in the distance r2. Hydrogen and methyl group are separated by the angle alpha.

CH₃: eps/kb(K) = 105.2, sigma(A) = 3.74, q(e) = 0.265

O: eps/kb(K) = 86.5, sigma(A) = 3.030, q(e) = 0.7

H: q(e) = 0.435

Group mass